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美国制动液标准 FMVSS-116-2002 DOT

49 CFR Ch. V (10–1–02 Edition)§571.115

§571.115[Reserved]

§571.116Standard No. 116; Motor ve-hicle brake fluids.

S1. Scope. This standard specifies re-quirements for fluids for use in hydrau-lic brake systems of motor vehicles, containers for these fluids, and labeling of the containers.

S2. Purpose. The purpose of this standard is to reduce failures in the hy-draulic braking systems of motor vehi-cles which may occur because of the manufacture or use of improper or con-taminated fluid.

S3. Application. This standard applies to all fluid for use in hydraulic brake systems of motor vehicles. In addition, S5.3 applies to passenger cars, multi-purpose passenger vehicles, trucks, buses, trailers, and motorcycles.

S4. Definitions.

Blister means a cavity or sac on the surface of a brake cup.

Brake fluid means a liquid designed for use in a motor vehicle hydraulic brake system in which it will contact elastomeric components made of sty-rene and butadiene rubber (SBR), ethylene and propylene rubber (EPR), polychloroprene (CR) brake hose inner tube stock or natural rubber (NR). Chipping means a condition in which small pieces are missing from the outer surface of a brake cup.

Duplicate samples means two samples of brake fluid taken from a single packaged lot and tested simulta-neously.

Hydraulic system mineral oil means a mineral-oil-based fluid designed for use in motor vehicle hydraulic brake sys-tems in which the fluid is not in con-tact with components made of SBR, EPR or NR.

Packager means any person who fills containers with brake fluid that are subsequently distributed for retail sale. Packaged lot is that quantity of brake fluid shipped by the manufacturer to the packager in a single container, or that quantity of brake fluid manufac-tured by a single plant run of 24 hours or less, through the same processing equipment and with no change in in-gredients.

Scuffing means a visible erosion of a portion of the outer surface of a brake cup.

A silicone base brake fluid (SBBF) is a brake fluid which consists of not less than 70 percent by weight of a diorgano polysiloxane.

Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500±10 gram deadweight on it, is drawn base down over a sheet of white bond paper placed on a firm flat sur-face.

Stickiness means a condition on the surface of a brake cup such that fibers will be pulled from a wad of U.S.P. ab-sorbent cotton when it is drawn across the surface.

S5. Requirements. This section speci-fies performance requirements for DOT 3, DOT 4 and DOT 5 brake fluids; re-quirements for brake fluid certifi-cation; and requirements for container sealing, labeling and color coding for brake fluids and hydraulic system min-eral oils. Where a range of tolerances is specified, the brake fluid shall meet the requirements at all points within the range.

S5.1Brake fluid. When tested in ac-cordance with S6, brake fluids shall meet the following requirements:

S5.1.1Equilibrium reflux boiling point (ERBP). When brake fluid is tested ac-cording to S6.1, the ERBP shall not be less than the following value for the grade indicated:

(a) DOT 3: 205 °C. (401 °F.).

(b) DOT 4: 230 °C. (446 °F.).

S5.1.2Wet ERBP. When brake fluid is tested according to S6.2, the wet ERBP shall not be less than the fol-lowing value for the grade indicated:

(a) DOT 3: 140 °C. (284 °F.).

(b) DOT 4: 155 °C. (311 °F.).

S5.1.3. Kinematic viscosities. When brake fluid is tested according to S6.3, the kinematic viscosities in square millimeters per second at stated tem-peratures shall be neither less than 1.5 mm2/s at 100 °C. (212 °F.) nor more than the following maximum value for the grade indicated:

(a) DOT 3: 1,500 mm2/s at minus 40 °C. (minus 40 °F.).

(b) DOT 4: 1,800 mm2/s at minus 40 °C. (minus 40 °F.).

Nat’l Highway Traffic Safety Admin., DOT§571.116 (c) DOT 5: 900 mm2/s at minus 40 °C.

(minus 40 °F.).

S5.1.4pH value. When brake fluid,

except DOT 5 SBBF, is tested according

to S6.4, the pH value shall not be less

than 7.0 nor more than 11.5.

S5.1.5Brake fluid stability.

S5.1.5.1High-temperature stability.

When brake fluid is tested according to

S6.5.3 the ERBP shall not change by

more than 3 °C. (5.4 °F.) plus 0.05° for

each degree that the ERBP of the fluid

exceeds 225 °C. (437 °F.).

S5.1.5.2Chemical stability. When

brake fluid, except DOT 5 SBBF, is

tested according to S6.5.4, the change

in temperature of the refluxing fluid

mixture shall not exceed 3.0 °C (5.4 °F.)

plus 0.05° for each degree that the

ERBP of the fluid exceeds 225 °C (437

°F.).

S5.1.6Corrosion. When brake fluid is

tested according to S6.6—

(a) The metal test strips shall not

show weight changes exceeding the

limits stated in Table I.

T ABLE I

Test strip material

Maximum permissible weight change, mg./sq. cm. of sur-

face

Steel, tinned iron, cast iron.................................0.2 Aluminum.. (1)

Brass, copper (4)

(b) Excluding the area of contact (13±1 mm. (1?2±1?32inch) measured from the bolt hole end of the test strip), the metal test strips shall not show pitting or etching to an extent discernible without magnification;

(d) No crystalline deposit shall form and adhere to either the glass jar walls or the surface of the metal strips;

(e) At the end of the test, sedimenta-tion of the water-wet brake fluid shall not exceed 0.10 percent by volume;

(f) The pH value of water-wet brake fluid, except DOT 5 SBBF, at the end of the test shall not be less than 7.0 nor more than 11.5;

(g) The cups at the end of the test shall show no disintegration, as evi-denced by blisters or sloughing;

(h) The hardness of the cup shall not decrease by more than 15 International Rubber Hardness Degrees (IRHD); and

(i) The base diameter of the cups shall not increase by more than 1.4 mm. (0.055 inch).

S5.1.7Fluidity and appearance at low temperature. When brake fluid is tested according to S6.7, at the storage tem-perature and for the storage times given in Table II—

(a) The fluid shall show no sludging, sedimentation, crystallization, or stratification;

(b) Upon inversion of the sample bot-tle, the time required for the air bubble

to travel to the top of the fluid shall not exceed the bubble flow times shown

in Table II; and

T ABLE II—F LUIDITY AND A PPEARANCE AT L OW

T EMPERATURES

Storage temperature

Storage

time

(hours)

Maximum

bubble

flow time

(seconds) Minus 40±2 °C. (minus 40±3.6 °F.) 144±4.010 Minus 50±2 °C. (minus 58±3.6 °F.) 6±0.235

S5.1.8Evaporation. When brake fluid

is tested according to S6.8—

(a) The loss by evaporation shall not exceed 80 percent by weight;

(b) The residue from the brake fluid after evaporation shall contain no pre-cipitate that remains gritty or abra-sive when rubbed with the fingertip; and

S5.1.9Water tolerance. (a) At low tem-perature. When brake fluid is tested ac-cording to S6.9.3(a)—

(1) The fluid shall show no sludging, sedimentation, crystallization, or stratification;

(2) Upon inversion of the centrifuge tube, the air bubble shall travel to the top of the fluid in not more than 10 sec-onds;

(3) If cloudiness has developed, the wet fluid shall regain its original clar-

ity and fluidity when warmed to room temperature; and

(b) At 60 °C. (140 °F.). When brake fluid

is tested according to S6.9.3(b)—

49 CFR Ch. V (10–1–02 Edition)§571.116

(1) The fluid shall show no stratifica-tion; and

(2) Sedimentation shall not exceed 0.15 percent by volume after centrifuging.

S5.1.10Compatibility.

(a) At low temperature. When brake fluid is tested according to S6.10.3(a), the test specimen shall show no sludging, sedimentation, or crystalliza-tion. In addition, fluids, except DOT 5 SBBF, shall show no stratification.

(b) At 60 °C. (140 °F.). When brake fluid is tested according to S6.10.3(b)—(1) Sedimentation shall not exceed 0.05 percent by volume after centrifuging; and

(2) Fluids, except DOT 5 SBBF, shall show no stratification.

S5.1.11Resistance to oxidation. When brake fluid is tested according to S6.11—

(a) The metal test strips outside the areas in contact with the tinfoil shall not show pitting or etching to an ex-tent discernible without magnification; (b) No more than a trace of gum shall

be deposited on the test strips outside the areas in contact with the tinfoil;

(d) The cast iron strips shall not change in weight by more than 0.3 mg./ sq. cm.

S5.1.12Effects on cups. When brake cups are subjected to brake fluid in ac-cordance with S6.12—

(a) The increase in the diameter of the base of the cups shall be not less than 0.15 mm. (0.006 inch) or more than

1.40 mm. (0.055 inch);

(b) The decrease in hardness of the cups shall be not more than 10 IRHD at

70 °C. (158 °F.) or more than 15 IRHD at 120 °C. (248 °F.), and there shall be no increase in hardness of the cups; and

S5.1.13Stroking properties. When brake fluid is tested according to S6.13—

(a) Metal parts of the test system shall show no pitting or etching to an extent discernible without magnifica-tion; (b) The change in diameter of any

cylinder or piston shall not exceed 0.13 mm. (0.005 inch);

(c) The average decrease in hardness of seven of the eight cups tested (six wheel cylinder and one master cylinder primary) shall not exceed 15 IRHD. Not more than one of the seven cups shall have a decrease in hardness greater than 17 IRHD;

(d) None of the eight cups shall be in an unsatisfactory operating condition as evidenced by stickiness, scuffing, blisters, cracking, chipping, or other change in shape from its original ap-pearance;

(e) None of the eight cups shall show an increase in base diameter greater than 0.90 mm (0.035 inch);

(f) The average lip diameter set of the eight cups shall not be greater than

65 percent.

(g) During any period of 24,000 strokes, the volume loss of fluid shall not exceed 36 milliliters;

(h) The cylinder pistons shall not freeze or function improperly through-out the test;

(i) The total loss of fluid during the 100 strokes at the end of the test shall not exceed 36 milliliters;

(j) The fluid at the end of the test shall show no formation of gels;

(k) At the end of the test the amount of sediment shall not exceed 1.5 percent by volume; and

(l) Brake cylinders shall be free of de-posits that are abrasive or that cannot be removed when rubbed moderately with a nonabrasive cloth wetted with ethanol.

S5.1.14 Fluid color. Brake fluid and hydraulic system mineral oil shall be of the color indicated:

DOT 3, DOT 4, and DOT 5.1 non-SBBF—color-less to amber.

DOT 5 SBBF—purple.

Hydraulic system mineral oil—green.

S5.2Packaging and labeling require-ments for motor vehicle brake fluids.

S5.2.1Container sealing. Each brake fluid or hydraulic system mineral oil container with a capacity of 177 mL or more shall be provided with a reseal-able closure that has an inner seal im-pervious to the packaged brake fluid. The container closure shall include a tamper-proof feature that will either be destroyed or substantially altered

Nat ’l Highway Traffic Safety Admin., DOT §571.116

when the container closure is initially opened.

S5.2.2Certification, marking, and la-beling.

S5.2.2.1Each manufacturer of a DOT

grade brake fluid shall furnish to each packager, distributor, or dealer to whom he delivers brake fluid, the fol-lowing information:

(a) A serial number identifying the production lot and the date of manu-facture of the brake fluid.

(b) The grade (DOT 3, DOT 4, DOT 5) of the brake fluid. If DOT 5 grade brake

fluid , it shall be further distinguished as ‘‘DOT 5 SILICONE BA SE ’’ or ‘‘DOT 5.1 NON-SILICONE BASE.’’

(d) Certification that the brake fluid

conforms to §571.116.

S5.2.2.2Each packager of brake fluid

shall furnish the information specified in paragraphs (a) through (g) of this S5.2.2.2 by clearly marking it on each brake fluid container or on a label (labels) permanently affixed to the con-tainer, in any location except a remov-able part such as a lid. After being sub-jected to the operations and conditions specified in S6.14, the information re-quired by this section shall be legible to an observer having corrected visual acuity of 20/40 (Snellen ratio) at a dis-tance of 305 mm, and any label affixed to the container in compliance with this section shall not be removable without its being destroyed or defaced. (a) Certification that the brake fluid conforms to §571.116. (b) The name of the packager of the brake fluid, which may be in code form. (c) The name and complete mailing address of the distributor. (d) A serial number identifying the packaged lot and date of packaging. (e) Designation of the contents as ‘‘DOT —MOTOR VEHICLE BR A

KE FLUID ’’ (Fill in DOT 3, DOT 4, DOT 5 SILICONE BASE, or DOT 5.1 NON-SIL-ICONE BASE as applicable). (f) The minimum wet boiling point in Fahrenheit of the DOT brake fluid in the container. (g) The following safety warnings in capital and lower case letters as indi-cated: (1) FOLLOW VEHICLE MA NUFA C-TURER ’S RECOMMEND A TIONS WHEN ADDING BRAKE FLUID.

(2) KEEP BRA KE FLUID CLEA N A ND DRY. Contamination with dirt, water, petroleum products or other ma-terials may result in brake failure or

costly repairs. (3) STORE BRA KE FLUID ONLY IN ITS ORIGINA L CONTA INER. KEEP CONTA INER CLEA N A ND TIGHTLY

CLOSED TO PREVENT A BSORPTION OF MOISTURE.

(4) CAUTION: DO NOT REFILL CON-TA INER, A ND DO NOT USE FOR OTHER LIQUIDS. (Not required for

containers with a capacity in excess of 19 L.)

S5.2.2.3Each packager of hydraulic system mineral oil shall furnish the in-formation specified in paragraphs (a)

through (e) of this S5.2.2.3 by clearly

marking it on each brake fluid con-tainer or on a label (labels) perma-nently affixed to the container, in any

location except a removable part such as a lid. A fter being subjected to the operations and conditions specified in

S6.14, the information required by this

section shall be legible to an observer

having corrected visual acuity of 20/40 (Snellen ratio) at a distance of 305 mm and any label affixed to the container in compliance with this section shall not be removable without its being de-stroyed or defaced. (a) The name of the packager of the hydraulic system mineral oil, which may be in code form. (b) The name and complete mailing address of the distributor. (c) A serial number identifying the packaged lot and date of packaging. (d) Designation of the contents as ‘‘HYDR A

ULIC SYSTEM MINER A

L OIL ’’ in capital letters at least 3 mm high. (e) The following safety warnings in capital and lower case letters as indi-cated: (1) FOLLOW VEHICLE MA NUFA C-TURER ’S RECOMMEND A

TIONS WHEN ADDING HYDRAULIC SYSTEM MINERAL OIL. (2) Hydraulic System Mineral Oil is NOT COMPA TIBLE with the rubber components of brake systems designed for use with DOT brake fluids.

49 CFR Ch. V (10–1–02 Edition)§571.116

(3) KEEP HYDR ULIC SYSTEM

MINERAL OIL CLEAN. Contamination

with dust or other materials may re-

sult in brake failure or costly repair.

(4) CAUTION: STORE HYDRA ULIC

SYSTEM MINERAL OIL ONLY IN ITS

ORIGINA L CONTA INER. KEEP CON-

T A INER CLE

ND TIGHTLY

CLOSED. DO NOT REFILL CON-TA INER OR USE OTHER LIQUIDS. (The last sentence is not required for containers with a capacity in excess of 19 L.)

S5.2.2.4 If a container for brake fluid or hydraulic system mineral oil is not normally visible but designed to be protected by an outer container or car-ton during use, the outer container or carton rather than the inner container shall meet the labeling requirements of S5.2.2.2 or S5.2.2.3, as appropriate.

S5.3Motor vehicle requirement. Each passenger car, multipurpose passenger vehicle, truck, bus, trailer, and motor-cycle that has a hydraulic brake sys-tem shall be equipped with fluid that has been manufactured and packaged in conformity with the requirements of this standard.

S6. Test procedures.

S6.1Equilibrium reflux boiling point. Determine the ERBP of a brake fluid by running duplicate samples accord-ing to the following procedure and averaging the results.

S6.1.1Summary of procedure. Sixty milliliters (ml.) of brake fluid are boiled under specified equilibrium con-ditions (reflux) at atmospheric pressure in a 100-ml. flask. The average tem-perature of the boiling fluid at the end of the reflux period, corrected for vari-ations in barometric pressure if nec-essary, is the ERBP.

S6.1.2Apparatus. (See Figure 1) The test apparatus shall consist of—

(a) Flask. (See Figure 2) A 100-ml. round-bottom, short-neck heat-resist-ant glass flask having a neck with a 19?38standard taper, female ground-glass joint and a side-entering tube, with an outside diameter of 10 millime-ters (mm.), which centers the ther-mometer bulb in the flask 6.5 mm. from the bottom;

(b) Condenser. A water-cooled, reflux, glass-tube type, condenser having a jacket 200 mm. in length, the bottom end of which has a 19?38standard-taper,

drip-tip, male ground-glass joint;

(c) Boiling stones. Three clean, unused silicon carbide grains (approximately 2 mm. (0.08 inch) in diameter, grit No. 8); (d) Thermometer. Standardized cali-brated partial immersion (76 mm.), solid stem, thermometers conforming

to the requirements for an ASTM 2C or

2F, and an A STM 3C or 3F thermom-eter; and

(e) Heat source. Variable autotransformer-controlled heating mantle designed to fit the flask, or an electric heater with rheostat heat con-

trol.

F IG. 1. B OILIN

G P OINT T EST A PPARATUS

Nat’l Highway Traffic Safety Admin., DOT§

571.116

F IG. 2. D ETAIL OF100 ML S HORT-N ECK F LASK

S6.1.3Preparation of apparatus. (a) Thoroughly clean and dry all glass-ware.

(b) Insert thermometer through the side tube until the tip of the bulb is 6.5 mm. (1?4inch) from the bottom center of the flask. Seal with a short piece of natural rubber, EPDM, SBR, or butyl tubing.

(d) Attach the flask to the condenser. When using a heating mantle, place the mantle under the flask and support it with a ring-clamp and laboratory-type stand, holding the entire assembly in place by a clamp. When using a rheo-stat-controlled heater, center a stand-ard porcelain or hard asbestos refrac-tory, having a diameter opening 32 to 38 mm., over the heating element and mount the flask so that direct heat is applied only through the opening in the refractory. Place the assembly in an area free from drafts or other types of sudden temperature changes. Con-nect the cooling water inlet and outlet tubes to the condenser. Turn on the cooling water. The water supply tem-perature shall not exceed 28 °C. (82.4 °F.) and the temperature rise through the condenser shall not exceed 2 °C. (3.6 °F.).

S6.1.4Procedure. A pply heat to the flask so that within 10±2 minutes the fluid is refluxing in excess of 1 drop per second. The reflux rate shall not exceed 5 drops per second at any time. Imme-diately adjust the heating rate to ob-tain an equilibrium reflux rate of 1 to 2 drops per second over the next 5±2 minutes. Maintain this rate for an ad-ditional 2 minutes, taking four tem-perature readings at 30–second inter-vals. Record the average of these as the observed ERBP. If no reflux is evident when the fluid temperature reaches 260 °C (500 °F), discontinue heating and re-port ERBP as in excess of 260 °C (500 °F).

S6.1.5Calculation. (a) Thermometer inaccuracy. Correct the observed ERBP by applying any correction factor ob-tained in standardizing the thermom-eter.

(b) Variation from standard barometric pressure. A pply the factor shown in Table III to calculate the barometric pressure correction to the ERBP.

T ABLE III—C ORRECTION FOR B AROMETRIC

P RESSURE

Observed ERBP corrected for

thermometer inaccuracy

Correction per 1 mm

difference in pressure a

°C. (

°F.)

100 °C. (212 °F.) to 190 °C. (374

°F.).............................................0.039(0.07) Over 190 °C. (374 °F.)..................0.04(0.08)

a To be added in case barometric pressure is below 760 mm.; to be subtracted in case barometric pressure is above 670 mm.

(c) If the two corrected observed ERBP’s agree within 2 °C. (4 °C. for brake fluids having an ERBP over 230 °C./446 °F.) average the duplicate runs as the ERBP; otherwise, repeat the en-tire test, averaging the four corrected observed values to determine the origi-nal ERBP.

S6.2Wet ERBP. Determine the wet ERBP of a brake fluid by running du-plicate samples according to the fol-lowing procedure.

S6.2.1.Summary of procedure. A 350 ml. sample of the brake fluid is hu-midified under controlled conditions; 350 ml. of SA E triethylene glycol monomethyl ether, brake fluid grade, referee material (TEGME) as described in appendix E of SA E Standard J1703 Nov. 83, ‘‘Motor Vehicle Brake Fluid,’’November 1983, is used to establish the end point for humidification. After hu-midification, the water content and

49 CFR Ch. V (10–1–02 Edition)§571.116

ERBP of the brake fluid are deter-mined.

S6.2.2Apparatus for humidification. (See Figure 3).

Test apparatus shall consist of—

(a) Glass jars. Four SAE RM–49 corro-sion test jars or equivalent screwtop, straight-sided, round glass jars each having a capacity of about 475 ml. and approximate inner dimensions of 100 mm. in height by 75 mm. in diameter, with matching lids having new, clean inserts providing water-vapor-proof seals;

(b) Desiccator and cover. Two bowl-form glass desiccators, 250-mm. inside diameter, having matching tubulated covers fitted with No. 8 rubber stop-pers; and

S6.2.3Reagents and materials. (a) Dis-tilled water, see S7.1.

(b) SAE TEGME referee material.

S6.2.4Preparation of apparatus. Lu-bricate the ground-glass joint of the desiccator. Pour 450±10 ml. of distilled water into each desiccator and insert perforated porcelain desiccator plates. Place the desiccators in an oven with temperature controlled at 50±1 °C. (122±1.8 °F.) throughout the humidi-fication procedure.

S6.2.5Procedure. Pour 350±5 ml. of brake fluid into an open corrosion test jar. Prepare in the same manner a du-plicate test fluid sample and two dupli-cate specimens of the SAE TEGME ref-

eree material (350±5 ml. of TEGME in

each jar). The water content of the

SA E TEGME fluid is adjusted to

0.50±0.05 percent by weight at the start

of the test in accordance with S7.2.

Place one sample each of the test brake

fluid and the prepared TEGME sample

into the same desiccator. Repeat for

the second sample of test brake fluid

and TEGME in a second desiccator.

Place the desiccators in the 50 °C. (122

°F.) controlled oven and replace desic-cator covers. At intervals, during oven

humidification, remove the rubber

stoppers in the tops of desiccators.

Using a long needled hypodermic sy-

ringe, take a sample of not more than

2 ml. from each TEGME sample and de-

termine its water content. Remove no

more than 10 ml. of fluid from each

SA E TEGME sample during the hu-

midification procedure. When the

water content of the SAE fluid reaches

3.70±0.05 percent by weight (average of

the duplicates). remove the two test

fluid specimens from their desiccators

and promptly cap each jar tightly.

Allow the sealed jars to cool for 60 to 90

minutes at 23°±5 °C. (73.4°±9 °F.). Meas-

ure the water contents of the test fluid

specimens in accordance with S7.2 and

determine their ERBP’s in accordance

with S6.1. If the two ERBPs agree with-

in 4 °C. (8 °F.), average them to deter-

mine the wet ERBP; otherwise repeat

and average the four individual ERBPs

as the wet ERBP of the brake fluid.

Nat ’l Highway Traffic Safety Admin., DOT §

571.116

S6.3 Kinematic viscosities. Determine the kinematic viscosity of a brake fluid in mm 2/s by the following proce-dure. Run duplicate samples at each of the specified temperatures, making two timed runs on each sample.

S6.3.1Summary of the procedure. The time is measured for a fixed volume of the brake fluid to flow through a cali-brated glass capillary viscometer under an accurately reproducible head and at a closely controlled temperature. The kinematic viscosity is then calculated from the measured flow time and the calibration constant of the viscometer. S6.3.2Apparatus.(a) Viscometers. Calibrated glass cap-illary-type viscometers, A STM D2515–66, ‘‘Standard Specification for Kine-matic Glass Viscometers,’’ measuring viscosity within the precision limits of S6.4.7. Use suspended level viscometers for viscosity measurements at low tem-peratures. Use Cannon-Fenske Routine or other modified Ostwald viscometers at ambient temperatures and above. (b) Viscometer holders and frames. Mount a viscometer in the constant-temperature bath so that the mounting tube is held within 1° of the vertical. (c) Viscometer bath. A transparent liq-uid bath of sufficient depth such that

49 CFR Ch. V (10–1–02 Edition)

§571.116at no time during the measurement will any portion of the sample in the viscometer be less than 2 cm. below the surface or less than 2 cm. above the bottom. The bath shall be cylindrical in shape, with turbulent agitation suf-ficient to meet the temperature con-trol requirements. For measurements within 15° to 100 °C. (60° to 212 °F.) the temperature of the bath medium shall not vary by more than 0.01 °C. (0.02 °F.) over the length of the viscometers, or between the positions of the viscometers, or at the locations of the thermometers. Outside this range, the variation shall not exceed 0.03 °C. (0.05 °F.). (d) Thermometers. Liquid-in-Glass Kinematic Viscosity Test Thermom-eters, covering the range of test tem-peratures indicated in Table IV and conforming to A STM E1–68, ‘‘Specifications for A STM Thermom-eters,’’ and in the IP requirements for IP Standard Thermometers. Stand-ardize before use (see S6.3.3(b)). Use two standardized thermometers in the bath.

T ABLE IV —K INEMATIC V ISCOSITY T HERMOMETERS

Temperature range

For tests at Subdivisions Thermometer number

°C.

°F.

°C. °F. °C. °F. ASTM

Minus 55.3 to minus 52.5..Minus 67.5 to minus 62.5Minus 55..Minus 67..0.050.174 F 69 F. or C. Minus 41.4 to minus 38.6..Minus 42.5 to minus 37.5Minus 40..Minus 40..0.050.173 F 68 F. or C. 98.6 to 101.4.....................

207.5 to 212.5...................

100...........

212...........

0.05

0.130 F 32 F. or C.

(e) Timing device. Stop watch or other

timing device graduated in divisions representing not more than 0.2 second, with an accuracy of at least ±0.05 per-cent when tested over intervals of 15 minutes. Electrical timing devices may be used when the current frequency is controlled to an accuracy of 0.01 per-cent or better.

S6.3.3Standardization.

(a) Viscometers. Use viscometers cali-brated in accordance with appendix 1 of A STM D445–65, ‘‘Viscosity of Trans-parent and Opaque Liquids (Kinematic and Dynamic Viscosities).’’ The cali-bration constant, C, is dependent upon the gravitational acceleration at the place of calibration. This must, there-fore, be supplied by the standardization laboratory together with the instru-ment constant. Where the acceleration of gravity, g, in the two locations dif-fers by more than 0.1 percent, correct the calibration constant as follows:

C 2=(g 2/g 1)×C 1where the subscripts 1 and 2 indicate

respectively the standardization lab-oratory and the testing laboratory.

(b) Thermometers. Check liquid-in-glass thermometers to the nearest 0.01 °C. (0.02 °F.) by direct comparison with a standardized thermometer. Kine-matic Viscosity Test Thermometers shall be standardized at ‘‘total immer-sion.’’ The ice point of standardized thermometers shall be determined be-fore use and the official corrections shall be adjusted to conform to the changes in ice points. (See ASTM E77–66, ‘‘Verification and Calibration of Liquid-in-Glass Thermometers.’’)

(c) Timers. Time signals are broadcast by the National Bureau of Standards, Station WWV, Washington, DC at 2.5, 5, 10, 15, 20, 25, 30, and 35 Mc/sec (MHz). Time signals are also broadcast by Sta-tion CHU from Ottawa, Canada, at 3.330, 7.335, and 14.670 Mc/sec, and Sta-tion MSF at Rugby, United Kingdom, at 2.5, 5, and 10 Mc/sec.

S6.3.4Procedure. (a) Set and main-tain the bath at the appropriate test temperature (see S5.1.3) within the lim-its specified in S6.3.2(c). Apply the nec-essary corrections, if any, to all ther-mometer readings.

(b) Select a clean, dry, calibrated vis-cometer giving a flow time not less

than its specified minimum, or 200 sec-onds, whichever is the greater. (c) Charge the viscometer in the

manner used when the instrument was

calibrated. Do not filter or dry the

brake fluid, but protect it from con-tamination by dirt and moisture dur-ing filling and measurements. (1) Charge the suspended level

viscometers by tilting about 30° from

Nat’l Highway Traffic Safety Admin., DOT§571.116 the vertical and pouring sufficient

brake fluid through the fill tube into

the lower reservoir so that when the

viscometer is returned to vertical posi-

tion the meniscus is between the fill

marks. For measurements below 0 °C.

(32 °F.), before placing the filled vis-

cometer into the constant temperature

bath, draw the sample into the working

capillary and timing bulb and insert

small rubber stoppers to suspend the

fluid in this position, to prevent accu-

mulation of water condensate on the

walls of the critical portions of the vis-

cometer.

A lternatively, fit loosely

packed drying tubes into the open ends of the viscometer to prevent water con-densation, but do not restrict the flow of the sample under test by the pres-sures created in the instrument.

(2) If a Cannon-Fenske Routine vis-cometer is used, charge by inverting and immersing the smaller arm into the brake fluid and applying vacuum to the larger arm. Fill the tube to the upper timing mark, and return the vis-cometer to an upright position.

(d) Mount the viscometer in the bath in a true vertical position (see S6.3.2(b)).

(e) The viscometer shall remain in the bath until it reaches the test tem-perature.

(f) A t temperatures below 0 °C. (32 °F.) conduct an untimed preliminary run by allowing the brake fluid to drain through the capillary into the lower reservoir after the test tempera-ture has been established.

(g) Adjust the head level of the brake fluid to a position in the capillary arm about 5 mm. above the first timing mark.

(h) With brake fluid flowing freely measure to within 0.2 second the time required for the meniscus to pass from the first timing mark to the second. If this flow time is less than the min-imum specified for the viscometer, or 200 seconds, whichever is greater, re-peat using a viscometer with a cap-illary of smaller diameter.

(i) Repeat S6.3.4 (g) and (h). If the two timed runs do not agree within 0.2 percent, reject and repeat using a fresh sample of brake fluid.

S6.3.5Cleaning the viscometers. (a) Periodically clean the instrument with chromic acid to remove organic depos-its. Rinse thoroughly with distilled water and acetone, and dry with clean

dry air.

(b) Between successive samples rinse

the viscometer with ethanol (isopropanol when testing DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered dry air through the viscometer until the last trace of solvent is removed.

S6.3.6Calculation. (a) The following viscometers have a fixed volume charged at ambient temperature, and

as a consequence C varies with test temperature: Cannon-Fenske Routine, Pinkevitch, Cannon-Manning Semi-Micro, and Cannon Fenske Opaque. To calculate C at test temperatures other than the calibration temperature for these viscometers, see A STM D2515–66,

‘‘Kinematic Glass Viscometers’’ or fol-

low instructions given on the manufac-turer’s certificate of calibration.

(b) A verage the four timed runs on

the duplicate samples to determine the kinematic viscosities.

S6.3.7Precision (at 95 percent con-fidence level).

(a) Repeatability. If results on dupli-

cate samples by the same operator dif-

fer by more than 1 percent of their mean, repeat the tests.

S6.4pH value. Determine the pH value of a brake fluid by running one sample according to the following pro-cedure.

S6.4.1Summary of the procedure. Brake fluid is diluted with an equal volume of an ethanol-water solution. The pH of the resultant mixture is measured with a prescribed pH meter assembly at 23 °C. (73.4 °F.).

S6.4.2Apparatus. The pH assembly consists of the pH meter, glass elec-trode, and calomel electrode, as speci-

fied in A ppendices A1.1, A1.2, and A1.3

of A STM D 1121–67, ‘‘Standard Method

of Test for Reserve A lkalinity of En-

gine A ntifreezes and A ntirusts.’’ The glass electrode is a full range type (pH

0–14), with low sodium error.

S6.4.3Reagents. Reagent grade chemicals conforming to the specifica-tions of the Committee on A nalytical Reagents of the A merican Chemical Society.

49 CFR Ch. V (10–1–02 Edition)§571.116

(a) Distilled water. Distilled water

(S7.1) shall be boiled for about 15 min-

utes to remove carbon dioxide, and pro-

tected with a soda-lime tube or its

equivalent while cooling and in stor-

age. (Take precautions to prevent con-

tamination by the materials used for

protection against carbon dioxide.) The

pH of the boiled distilled water shall be

between 6.2 and 7.2 at 25 °C. (77 °F.).

(b) Standard buffer solutions. Prepare

buffer solutions for calibrating the pH

meter and electrode pair from salts

sold specifically for use, either singly

or in combination, as pH standards.

Dry salts for 1 hour at 110 °C. (230 °F.)

before use except for borax which shall

be used as the decahydrate. Store solu-

tions with pH less than 9.5 in bottles of

chemically resistant glass or poly-

ethylene. Store the alkaline phosphate

solution in a glass bottle coated inside

with paraffin. Do not use a standard

with an age exceeding three months.

(1) Potassium hydrogen phthalate

buffer solution (0.05 M, pH=4.01 at 25 °C.

(77 °F.)). Dissolve 10.21 g. of potassium

hydrogen phthalate (KHC8H4O4) in dis-

tilled water. Dilute to 1 liter.

(2) Neutral phosphate buffer solution

(0.025 M with respect to each phosphate

salt, pH=6.86 at 25 °C. (77 °F.)). Dissolve

3.40 g. of potassium dihydrogen phos-

phate (KH2PO4) and 3.55 g. of anhy-

drous disodium hydrogen phosphate

(Na2HPO4) in distilled water.

(3) Borax buffer solution (0.01 M,

pH=9.18 at 25 °C. (77 °F.)). Dissolve 3.81

g. of disodium tetraborate decahydrate

(Na2B4O7°10H2 O) in distilled water, and dilute to 1 liter. Stopper the bottle

except when actually in use.

(4) A lkaline phosphate buffer solu-

tion (0.01 M trisodium phosphate,

pH=11.72 at 25 °C. (77 °F.)). Dissolve 1.42

g. of anhydrous disodium hydrogen

phosphate (Na2HPO4) in 100 ml. of a 0.1

M carbonate-free solution of sodium

hydroxide. Dilute to 1 liter with dis-

tilled water.

(5) Potassium chloride electrolyte.

Prepare a saturated solution of potas-

sium chloride (KCl) in distilled water.

by volume of ethanol (S7.3) add 20 parts

by volume of distilled water. A djust

the pH of the mixture to 7±0.1 using 0.1

N sodium hydroxide (NaOH) solution. If

more than 4 ml. of NaOH solution per liter of mixture is required for neutral-ization, discard the mixture.

S6.4.4Preparation of electrode system.

(a) Maintenance of electrodes. Clean the glass electrode before using by im-mersing in cold chromic-acid cleaning solution. Drain the calomel electrode and fill with KCl electrolyte, keeping level above that of the mixture at all times. When not in use, immerse the lower halves of the electrodes in dis-tilled water, and do not immerse in the mixture for any appreciable period of time between determinations.

(b) Preparation of electrodes. Condition new glass electrodes and those that have been stored dry as recommended by the manufacturer. Before and after using, wipe the glass electrode thor-oughly with a clean cloth, or a soft ab-sorbent tissue, and rinse with distilled water. Before each pH determination, soak the prepared electrode in distilled water for at least 2 minutes. Imme-diately before use, remove any excess water from the tips of the electrode.

S6.4.5Standardization of the pH as-sembly and testing of the electrodes. (a) Immediately before use, standardize the pH assembly with a standard buffer solution. Then use a second standard buffer solution to check the linearity of the response of the electrodes at dif-ferent pH values, and to detect a faulty glass electrode or incorrect tempera-ture compensation. The two buffer so-lutions bracket the anticipated pH value of the test brake fluid.

(b) A llow instrument to warm up, and adjust according to the manufac-turer’s instructions. Immerse the tips of the electrodes in a standard buffer solution and allow the temperature of the buffer solution and the electrodes to equalize. Set the temperature knob at the temperature of the buffer solu-tion. A djust the standardization or asymmetry potential control until the meter registers a scale reading, in pH units, equal to the known pH of the standardizing buffer solution.

(c) Rinse the electrodes with distilled water and remove excess water from the tips. Immerse the electrodes in a second standard buffer solution. The reading of the meter shall agree with the known pH of the second standard

Nat’l Highway Traffic Safety Admin., DOT§571.116

buffer solution within ±0.05 unit with-out changing the setting of the stand-ardization of asymmetry potential con-trol.

(d) A faulty electrode is indicated by failure to obtain a correct value for the pH of the second standard buffer solu-tion after the meter has been standard-ized with the first.

S6.4.6Procedure. To 50±1 ml. of the test brake fluid add 50±1 ml. of the eth-anol-water (S6.4.3(c)) and mix thor-oughly. Immerse the electrodes in the mixture. A llow the system to come to equilibrium, readjust the temperature compensation if necessary, and take the pH reading.

S6.5Fluid stability. Evaluate the heat and chemical stability of a brake fluid by the following procedure, run-ning duplicate samples for each test and averaging the results.

S6.5.1Summary of the procedure. The degradation of the brake fluid at ele-vated temperature, alone or in a mix-ture with a reference fluid, is evaluated by determining the change in boiling point after a period of heating under reflux conditions.

S6.5.2Apparatus. Use the apparatus and preparation specified in S6.1.2 and S6.1.3.

S6.5.3High temperature stability.

S6.5.3.1Procedure. (a) Heat a new 60±1 ml. sample of the brake fluid to 185°±2 °C. (365°±3.6 °F.). Hold at this temperature for 120±5 minutes. Bring to a reflux rate in excess of 1 drop per second within 5 minutes. The reflux rate should not exceed 5 drops per sec-ond at any time. Over the next 5±2 min-utes adjust the heating rate to obtain an equilibrium reflux rate of 1 to 2 drops per second. Maintain this rate for an additional 2 minutes, taking four temperature readings at 30–second in-tervals. A verage these as the observed ERBP. If no reflux is evident when the fluid temperature reaches 260 °C. (500 °F), discontinue heating and report ERBP as in excess of 260 °C. (500 °F.).

S6.5.3.2Calculation. Correct the ob-served ERBP for thermometer and bar-ometric pressure factors according to S6.1.5 (a) and (b). Average the corrected ERBP’s of the duplicate samples. The difference between this average and the original ERBP obtained in S6.1 is the change in ERBP of the fluid.

S6.5.4Chemical stability.

S6.5.4.1Materials. S

E RM–66–04 Compatibility Fluid as described in ap-pendix B of SA E Standard J1703 JA N 1995, ‘‘Motor Vehicle Brake Fluid.’’(SA E RM–66–03 Compatibility Fluid as described in appendix A of SAE Stand-ard J1703 Nov83, ‘‘Motor Vehicle Brake Fluid,’’ November 1983, may be used in place of SAE RM–66–04 until January 1, 1995.)

S6.5.4.2Procedure. (a) Mix 30 ± 1 ml. of the brake fluid with 30 ± 1 ml. of SAE RM–66–04 Compatibility Fluid in a boiling point flask (S6.1.2(a)). Deter-mine the initial ERBP of the mixture by applying heat to the flask so that the fluid is refluxing in 10 ± 2 minutes at a rate in excess of 1 drop per second, but not more than 5 drops per second. Note the maximum fluid temperature observed during the first minute after the fluid begins refluxing at a rate in excess of 1 drop per second. Over the next 15 ± 1 minutes, adjust and main-tain the reflux rate at 1 to 2 drops per second. Maintain this rate for an addi-tional 2 minutes, recording the average value of four temperature readings taken at 30 second intervals as the final ERBP.

(b) Thermometer and barometric cor-rections are not required.

S6.5.4.3Calculation. The difference between the initial ERBP and the final average temperature is the change in temperature of the refluxing mixture. Average the results of the duplicates to the nearest 0.5 °C (1.0 °F).

S6.6Corrosion. Evaluate the corro-siveness of a brake fluid by running du-plicate samples according to the fol-lowing procedure.

S6.6.1Summary of the procedure. Six specified metal corrosion test strips are polished, cleaned, and weighed, then assembled as described. Assembly is placed on a standard wheel cylinder cup in a corrosion test jar, immersed in the water-wet brake fluid, capped and placed in an oven at 100 °C. (212 °F.) for 120 hours. Upon removal and cooling, the strips, fluid, and cups are examined and tested.

S6.6.2Equipment. (a) Balance. An an-alytical balance having a minimum ca-pacity of 50 grams and capable of weighing to the nearest 0.1 mg.

49 CFR Ch. V (10–1–02 Edition)§571.116

(b) Desiccators. Desiccators con-taining silica gel or other suitable des-iccant.

(d) Micrometer. A machinist’s mi-crometer 25 to 50 mm. (1 to 2 inches) capacity, or an optical comparator, ca-pable of measuring the diameter of the SBR wheel cylinder (WC) cups to the nearest 0.02 mm. (0.001 inch).

S6.6.3Materials. (a) Corrosion test strips. Two sets of strips from each of the metals listed in appendix C of SAE Standard J1703b. Each strip shall be ap-proximately 8 cm. long, 1.3 cm. wide, not more than 0.6 cm. thick, and have

a surface area of 25±5 sq. cm. and a hole

4 to

5 mm. (0.1

6 to 0.20 inch) in diame-ter on the centerline about 6 mm. from one end. The hole shall be clean and free from burrs. Tinned iron strips shall be unused. Other strips, if used, shall not be employed if they cannot be polished to a high finish.

(b) SBR cups. Two unused standard SAE SBR wheel cylinder (WC) cups, as specified in S7.6.

(c) Corrosion test jars and lids. Two screw-top straight-sided round glass jars, each having a capacity of approxi-mately 475 ml. and inner dimensions of approximately 100 mm. in height and 75 mm. in diameter, and a tinned steel lid (no insert or organic coating) vented with a hole 0.8±0.1 mm. (0.031±0.004 inch) in diameter (No. 68 drill).

(d) Machine screws and nuts. Clean, rust and oil-free, uncoated mild steel round or fillister head machine screws, size 6 or 8–32 UNC–Class 2A, five-eighths or three-fourths inch long (or equivalent metric sizes), and matching uncoated nuts.

(e) Supplies for polishing strips. Water-proof silicon carbide paper, grit No. 320 ; grade 00 steel wool, lint-free polishing cloth.

(f) Distilled water as specified in S7.1.

(g) Ethanol as specified in S7.3.

(h) Isopropanol as specified in S7.7.

S6.6.4Preparation.

(a) Corrosion test strips. Except for the tinned iron strips, abrade corrosion test strips on all surface areas with sil-icon carbide paper wet with ethanol (isopropanol when testing DOT 5 SBBF fluids) until all surface scratches, cuts and pits are removed. Use a new piece

of paper for each different type of metal. Polish the strips with the 00 grade steel wool. Wash all strips, in-cluding the tinned iron and the assem-

bly hardware, with ethanol (isopropanol when testing DOT 5 SBBF fluids); dry the strips and assembly hardware with a clean lint free cloth or

use filtered compressed air and place

the strips and hardware in a desiccator containing silica gel or other suitable desiccant and maintained at 23°±5 °C. (73.4°±9 °F.), for at least 1 hour. Handle

the strips with forceps after polishing. Weigh and record the weight of each strip to the nearest 0.1 mg. A ssemble

the strips on a clean dry machine screw, with matching plain nut, in the order of tinned iron, steel, aluminum, cast iron, brass, and copper. Bend the strips, other than the cast iron, so that there is a separation of 3±1?2mm. (1?8±1?64 inch) between adjacent strips for a dis-tance of about 5 cm. (2 inches) from the

free end of the strips. (See Figure 4.) Tighten the screw on each test strip as-sembly so that the strips are in elec-trolytic contact, and can be lifted by either of the outer strips (tinned iron

or copper) without any of the strips moving relative to the others when held horizontally. Immerse the strip assemblies in 90 percent ethyl alcohol.

Dry with dried filtered compressed air, then desiccate at least 1 hour before

use.

F IG. 4. C ORROSION S TRIP A SSEMBLY

(b) SBR WC cups. Measure the base diameters of the two standard SBR

Nat’l Highway Traffic Safety Admin., DOT§571.116

cups, using an optical comparator or micrometer, to the nearest 0.02 mm.

(0.001 inch) along the centerline of the SA E and rubber-type identifications and at right angles to this centerline. Take the measurements at least 0.4 mm. (0.015 inch) above the bottom edge and parallel to the base of the cup. Dis-card any cup if the two measured diam-eters differ by more than 0.08 mm.

(0.003 inch). A verage the two readings on each cup. Determine the hardness of the cups according to S7.4.

S6.6.5Procedure. Rinse the cups in ethanol (isopropanol when testing DOT

5 SBBF fluids) for not more than 30 seconds and wipe dry with a clean lint-free cloth. Place one cup with lip edge facing up, in each jar. Insert a metal strip assembly inside each cup with the fastened end down and the free end ex-tending upward. (See Figure 5.) When testing brake fluids, except DOT 5 SBBF, mix 760 ml. of brake fluid with 40 ml. of distilled water. When testing DOT 5 SBBF’s, humidify 800 ml. of brake fluid in accordance with S6.2, eliminating determination of the ERBP. Using this water-wet mixture, cover each strip assembly to a min-imum depth of 10 mm. above the tops of the strips. Tighten the lids and place the jars for 120±2 hours in an oven maintained at 100°±2 °C. (212°±3.

6 °F.).

A llow the jars to cool at 23°±5 °C.

(73.4°±9 °F.) for 60 to 90 minutes. Imme-diately remove the strips from the jars using forceps, agitating the strip as-sembly in the fluid to remove loose ad-hering sediment. Examine the test strips and jars for adhering crystalline deposits. Disassemble the metal strips, and remove adhering fluid by flushing with water; clean each strip by wiping with a clean cloth wetted with ethanol (isopropanol when testing DOT 5 fluids). Examine the strips for evidence

of corrosion and pitting. Disregard staining or discoloration. Place the strips in a desiccator containing silica gel or other suitable desiccant, main-tained at 23°±5 °C. (73.4°±9 °F.), for at least 1 hour. Weigh each strip to the nearest 0.1 mg. Determine the change in weight of each metal strip. Average the results for the two strips of each type of metal. Immediately following the cooling period, remove the cups from the jars with forceps. Remove loose adhering sediment by agitation of the cups in the mixture. Rinse the cups in ethanol (isopropanol when testing DOT 5 fluids) and air-dry. Examine the cups for evidence of sloughing, blisters, and other forms of disintegration. Measure the base diameter and hard-ness of each cup within 15 minutes after removal from the mixture. Exam-ine the mixture for gelling. Agitate the mixture to suspend and uniformly dis-perse sediment. From each jar, transfer a 100 ml. portion of the mixture to an ASTM cone-shaped centrifuge tube. De-termine the percent sediment after centrifuging as described in S7.5. Meas-ure the pH value of the corrosion text fluid according to S6.4.6. Measure the pH value of the test mixture according

to S6.4.6.

F IG. 5. C ORROSION T EST A PPARATUS

S6.6.6Calculation. (a) Measure the area of each type of test strip to the nearest square centimeter. Divide the average change in mass for each type by the area of that type.

(b) Note other data and evaluations indicating compliance with S5.1.6. In the event of a marginal pass on inspec-tion by attributes, or of a failure in one of the duplicates, run another set of duplicate samples. Both repeat samples shall meet all requirements of S5.1.6.

S6.7Fluidity and appearance at low temperatures. Determine the fluidity and appearance of a sample of brake fluid at each of two selected tempera-tures by the following procedure.

49 CFR Ch. V (10–1–02 Edition)§571.116

S6.7.1Summary of procedure. Brake fluid is chilled to expected minimum exposure temperatures and observed for clarity, gellation, sediment, separa-tion of components, excessive viscosity

or thixotropy.

S6.7.2Apparatus. (a) Oil sample bot-tle. Two clear flint glass 4–ounce bot-

tles made especially for sampling oil and other liquids, with a capacity of approximately 125 ml., an outside di-ameter of 37±0.05 mm. and an overall height of 165±2.5 mm.

(b) Cold chamber. A n air bath cold chamber capable of maintaining stor-age temperatures down to minus 55 °C. (minus 67 °F.) with an accuracy of ±2

°C. (3.6 °F.).

S6.7.3Procedure. (a) Place 100±1 ml.

of brake fluid at room temperature in

an oil sample bottle. Stopper the bottle with an unused cork and place in the cold chamber at the higher storage temperature specified in Table II (S5.1.7(c)). After 144±4 hours remove the bottle from the chamber, quickly wipe

it with a clean, lint-free cloth, satu-rated with ethanol (isopropanol when testing DOT 5 fluids) or acetone. Exam-

ine the fluid for evidence of sludging, sedimentation, crystallization, or stratification. Invert the bottle and de-termine the number of seconds re-quired for the air bubble to travel to the top of the fluid. Let sample warm

to room temperature and examine.

(b) Repeat S6.7.3(a), substituting the lower cold chamber temperature speci-fied in Table II, and a storage period of

6 hours ±12 minutes.

N OTE: Test specimens from either storage temperature may be used for the other only after warming up to room temperature.

S6.8Evaporation. The evaporation residue, and pour point of the evapo-ration residue of brake fluid, are deter-mined by the following procedure. Four replicate samples are run.

S6.8.1Summary of the procedure. The volatile diluent portion of a brake fluid

is evaporated in an oven at 100 °C. (212

°F.). The nonvolatile lubricant portion (evaporation residue) is measured and examined for grittiness; the residues are then combined and checked to as-sure fluidity at minus 5 °C. (23 °F.).

S6.8.2Apparatus.(a) Petri dishes. Four covered glass

petri dishes approximately 100 mm. in

diameter and 15 mm. in height.

(b) Oven. A top-vented gravity-con-

vection oven capable of maintaining a

temperature of 100°±2 °C. (212°±3.6 °F.).

pacity of at least 100 grams, capable of

weighing to the nearest 0.01 gram, and

suitable for weighing the petri dishes.

(d) Oil sample bottle. A glass sample

bottle as described in S6.7.2(a).

(e) Cold chamber. Air bath cold cham-

ber capable of maintaining an oil sam-

ple bottle at minus 5°±1 °C. (23°±2 °F.).

(f) Timing device. A timing device as

described in S6.3.2(e).

S6.8.3Procedure. Obtain the tare

weight of each of the four covered petri

dishes to the nearest 0.01 gram. Place

25±1 ml. of brake fluid in each dish, re-

place proper covers and reweigh. Deter-

mine the weight of each brake fluid

test specimen by the difference. Place

the four dishes, each inside its inverted

cover, in the oven at 100°±2 °C. (212°±4

°F.) for 46±2 hours. (Note: Do not simul-taneously heat more than one fluid in

the same oven.) Remove the dishes

from the oven, allow to cool to 23°±5 °C.

(73.4°±9 °F.), and weigh. Return to the

oven for an additional 24±2 hours. If at

the end of 72±4 hours the average loss

by evaporation is less than 60 percent,

discontinue the evaporation procedure

and proceed with examination of the

residue. Otherwise, continue this pro-

cedure either until equilibrium is

reached as evidenced by an incre-

mental mass loss of less than 0.25 gram

in 24 hours on all individual dishes or

for a maximum of 7 days. During the

heating and weighing operation, if it is

necessary to remove the dishes from

the oven for a period of longer than 1

hour, the dishes shall be stored in a

desiccator as soon as cooled to room

temperature. Calculate the percentage

of fluid evaporated from each dish. Ex-

amine the residue in the dishes at the

end of 1 hour at 23°±5 °C. (73.4°±9 °F.).

Rub any sediment with the fingertip to

determine grittiness or abrasiveness.

Combine the residues from all four

dishes in a 118 mL (4-ounce) oil-sample

bottle and store vertically in a cold

chamber at minus 5°±1 °C. (23°±5 °F.) for

60±10 minutes. Quickly remove the bot-

tle and place in the horizontal position.

Nat’l Highway Traffic Safety Admin., DOT§571.116

The residue must flow at least 5 mm (0.2 inch) along the tube within 5 sec-onds.

S6.8.4Calculation. The average of the percentage evaporated from all four dishes is the loss by evaporation.

S6.9Water tolerance. Evaluate the water tolerance characteristics of a brake fluid by running one test speci-men according to the following proce-dure.

S6.9.1Summary of the procedure.

Brake fluid, except DOT 5 SBBF, is diluted with 3.5 percent water (DOT 5 SBBF is humidified), then stored at minus 40 °C. (minus 40 °F.) for 120 hours. The cold, water-wet fluid is first examined for clarity, stratification, and sedimentation, then placed in an oven at 60 °C. (140 °F.) for 24 hours. On removal, it is again examined for strat-ification, and the volume percent of sediment determined by centrifuging.

S6.9.2Apparatus.

(a) Centrifuge tube. See S7.5.1(a).

(b) Centrifuge. See S7.5.1(b).

(d) Oven. Gravity or forced convec-tion oven.

(e) Timing device. See S6.3.2(e).

S6.9.3Procedure.

(a) At low temperature. Humidify 100±1 ml. of DOT 5 SBBF brake fluid in ac-cordance with S6.2 eliminating deter-mination of the ERBP. When testing brake fluids except DOT 5 SBBF, mix 3.5±0.1 ml. of distilled water with 100±1 ml. of the brake fluid; pour into a cen-trifuge tube. Stopper the tube with a clean cork and place in the cold cham-ber maintained at minus 40±2 °C. (minus 40±3.6 °F.). A fter 120 hours±2 hours remove the tube, quickly wipe with clean lint-free cloth saturated with ethanol or acetone and examine the fluid for evidence of sludging, sedi-mentation, crystallization, or strati-fication. Invert the tube and determine the number of seconds required for the air bubble to travel to the top of the fluid. (The air bubble is considered to have reached the top of the fluid when the top of the bubble reaches the 2 ml. graduation of the centrifuge tube.) If the wet fluid has become cloudy, warm to 23±5 °C. (73.4±9 °F.) and note appear-ance and fluidity.

(b) At 60 °C. (140 °F.). Place tube and brake fluid from S6.9.3(a) in an oven maintained at 60°±2 °C. (140°±3.6 °F.) for 24±2 hours. Remove the tube and imme-diately examine the contents for evi-dence of stratification. Determine the percent sediment by centrifuging as de-scribed in S7.5.

S6.10Compatibility. The compat-ibility of a brake fluid with other brake fluids shall be evaluated by run-ning one test sample according to the following procedure.

S6.10.1Summary of the procedure.

Brake fluid is mixed with an equal volume of SAE RM–66–04 Compatibility Fluid, then tested in the same way as for water tolerance (S6.9) except that the bubble flow time is not measured. This test is an indication of the com-patibility of the test fluid with other motor vehicle brake fluids at both high and low temperatures.

S6.10.2Apparatus and materials.

(a) Centrifuge tube. See S7.5.1(a).

(b) Centrifuge. See S7.5.1(b).

(d) Oven. See S6.9.2(d)

(e) SAE RM–66–04 Compatibility Fluid.

A s described in appendix

B of SA E Standard J1703 JA N 1995 ‘‘Motor Vehi-cle Brake Fluid.’’ (SAE RM–66–03 Com-patibility Fluid as described in appen-dix A of SA E Standard J1703 NOV83, ‘‘Motor Vehicle Brake Fluid,’’ Novem-ber 1983, may be used in place of SA E RM–66–04 until January 1, 1995.)

S6.10.3Procedure.

(a) At low temperature.

Mix 50±0.5 mL of brake fluid with 50±0.5 mL of SA E RM–66–04 Compat-ibility Fluid. Pour this mixture into a centrifuge tube and stopper with a clean dry cork. Place tube in the cold chamber maintained at minus 40°±2 °C. (minus 40°±4 °F). A fter 24±2 hours, re-move tube, quickly wipe with a clean lint-free cloth saturated with ethanol (isopropanol when testing DOT 5 fluids) or acetone. Examine the test specimen for evidence of slugging, sedimenta-tion, or crystallization. Test fluids, ex-cept DOT 5 SBBF, shall be examined for stratification.

S6.11Resistance to oxidation. The stability of a brake fluid under oxidative conditions shall be evaluated by running duplicate samples accord-ing to the following procedure.

S6.11.1Summary of procedure.

49 CFR Ch. V (10–1–02 Edition)§571.116

Brake fluids, except DOT 5 SBBF, are activated with a mixture of approxi-mately 0.2 percent benzoyl peroxide and 5 percent water. DOT 5 SBBF is hu-midified in accordance with S6.2 elimi-nating determination of the ERBP, and then approximately 0.2 percent benzoyl peroxide is added. A corrosion test strip assembly consisting of cast iron and an aluminum strip separated by tinfoil squares at each end is then rest-ed on a piece of SBR WC cup positioned so that the test strip is half immersed in the fluid and oven aged at 70 °C. (158 °F.) for 168 hours. At the end of this pe-riod, the metal strips are examined for pitting, etching, and loss of mass.

S6.11.2Equipment.

(a) Balance. See S6.6.2(a).

(b) Desiccators. See S6.6.2(b).

(d) Three glass test tubes approxi-mately 22 mm. outside diameter by 175 mm. in length.

S6.11.3Reagents and materials.

(a) Benzoyl peroxide, reagent grade, 96 percent. (Benzoyl peroxide that is brownish, or dusty, or has less than 90 percent purity, must be discarded.) Re-agent strength may be evaluated by A STM E298–68, ‘‘Standard Methods for Assay of Organic Peroxides.’’

(b) Corrosion test strips. Two sets of cast iron and aluminum metal test strips as described in appendix C of SAE Standard J1703b.

(0.0008 and 0.0024 inch) in thickness. The foil shall be at least 99.9 percent tin and contain not more than 0.025 percent lead.

(d) SBR cups. Two unused, approxi-mately one-eighth sections of a stand-ard SA E SBR WC cup (as described in S7.6).

(e) Machine screw and nut. Two clean oil-free, No. 6 or 8–32×3?8￥ or 1?2–inch long (or equivalent metric size), round or fillister head, uncoated mild steel machine screws, with matching plain nuts.

S6.11.4Preparation.

(a) Corrosion test strips. Prepare two sets of aluminum and cast iron test strips according to S6.6.4(a) except for assembly. Weigh each strip to the near-est 0.1 mg. and assemble a strip of each metal on a machine screw, separating the strips at each end with a piece of tinfoil. Tighten the nut enough to hold both pieces of foil firmly in place.

(b) Test mixture.Place 30±1 ml. of the brake fluid under test in a 22 by 175 mm. test tube. For all fluids except DOT 5 SBBF, add 0.060±.002 grams of benzoyl peroxide, and 1.50±0.05 ml. of distilled water. For DOT 5 SBBF, use test fluid humidified in accordance with S6.2, and add only the benzoyl peroxide. Stopper the tube loosely with

a clean dry cork, shake, and place in an oven for 2 hours at 70°±2 °C. (158°±3.6

°F.). Shake every 15 minutes to effect solution of the peroxide, but do not wet cork. Remove the tube from the oven and allow to cool to 23°±5 °C. (73.4°±9

°F.) Begin testing according to para-graph S6.11.5 not later than 24 hours after removal of tube from oven.

S6.11.5Procedure. Place a one-eighth SBR cup section in the bottom of each tube. A dd 10 ml. of prepared test mix-ture to each test tube. Place a metal-strip assembly in each, the end of the strip without the screw resting on the rubber, and the solution covering about one-half the length of the strips. Stop-

per the tubes with clean dry corks and store upright for 70±2 hours at 23°±5 °C. (73.4°±9 °F.). Loosen the corks and place the tubes for 168±2 hours in an oven maintained at 70°±2 °C. (158°±3.6 °F.).

A fterwards remove and disassemble strips. Examine the strips and note any gum deposits. Wipe the strips with a clean cloth wet with ethanol (isopropanol when testing DOT 5 fluids) and note any pitting, etching or rough-ening of surface disregarding stain or discoloration. Place the strips in a des-iccator over silica gel or other suitable desiccant, at 23°±5 °C. (73.4°±9 °F.) for at least 1 hour. Again weigh each strip to the nearest 0.1 mg.

S6.11.6Calculation. Determine corro-sion loss by dividing the change in mass of each metal strip by the total surface area of each strip measured in square millimeters (mm2), to the near-

est square millimeter (mm2). A verage the results for the two strips of each type of metal, rounding to the nearest 0.05 mg. per 100 square millimeter (mm2). If only one of the duplicates fails for any reason, run a second set of

Nat ’l Highway Traffic Safety Admin., DOT §571.116

duplicate samples. Both repeat samples shall meet all requirements of S5.1.11. S6.12Effect on SBR cups. The effects of a brake fluid in swelling, softening, and otherwise affecting standard SBR WC cups shall be evaluated by the fol-lowing procedure. S6.12.1Summary of the procedure. Four standard SA E SBR WC cups are measured and their hardnesses deter-mined. The cups, two to a jar, are im-mersed in the test brake fluid. One jar is heated for 70 hours at 70 °C. (158 °F), and the other for 70 hours at 120 °C (248 °F). A fterwards, the cups are washed, examined for disintegration, remeas-ured and their hardnesses redeter-mined.

S6.12.2Equipment and supplies.

(a) Oven. See S6.6.2(c).

(b) Glass jars and lids. Two screw-top,

straight-sided round glass jars, each

having a capacity of approximately 250

ml. and inner dimensions of approxi-mately 125 mm. in height and 50 mm. in diameter, and a tinned steel lid (no insert or organic coating).

S6.12.3Preparation. Measure the base diameters of the SBR cups as de-scribed in S6.6.4(b), and the hardness of each as described in S7.4.

S6.12.4Procedure. Wash the cups in 90 percent ethanol (isopropanol when testing DOT 5 fluids) (see S7.3), for not longer than 30 seconds and quickly dry with a clean, lint-free cloth. Using for-ceps, place two cups into each of the two jars; add 75 ml. of brake fluid to each jar and cap tightly. Place one jar in an oven held at 70°±2 °C. (158±3.6 °F.) for 70±2 hours. Place the other jar in an

oven held at 120°±2 °C. (248°±3.6 °F.) for

70±2 hours. Allow each jar to cool for 60

to 90 minutes at 23°±5 °C. (73.4°±9 °F.). Remove cups, wash with ethanol (isopropanol when testing DOT 5 fluids) for not longer than 30 seconds, and quickly dry. Examine the cups for dis-integration as evidenced by stickiness, blisters, or sloughing. Measure the base diameter and hardness of each cup within 15 minutes after removal from the fluid. S6.12.5Calculation. (a) Calculate the change in base diameter for each cup. If the two values, at each temperature, do not differ by more than 0.10 mm. (0.004 inch) average them to the nearest 0.02 mm. (0.001 inch). If the two values differ by more than 0.10 mm., repeat the test at the appropriate tempera-ture and average the four values as the change in base diameter. (b) Calculate the change in hardness

for each cup. The average of the two values for each pair is the change in hardness. (c) Note disintegration as evidenced

by stickiness, blisters, or sloughing.

S6.13Stroking properties. Evaluate the lubricating properties, component compatibility, resistance to leakage, and related qualities of a brake fluid by running one sample according to the following procedures.

S6.13.1Summary of the procedure.

Brake fluid is stroked under controlled

conditions at an elevated temperature

in a simulated motor vehicle hydraulic

braking system consisting of three

slave wheel cylinders and an actuating

master cylinder connected by steel tub-ing. Referee standard parts are used.

A ll parts are carefully cleaned, exam-ined, and certain measurements made immediately prior to assembly for test. During the test, temperature, rate of pressure rise, maximum pressure, and

rate of stroking are specified and con-trolled. The system is examined peri-odically during stroking to assure that excessive leakage of fluid is not occur-ring. A fterwards, the system is torn down. Metal parts and SBR cups are examined and remeasured. The brake fluid and any resultant sludge and de-bris are collected, examined, and test-ed.

S6.13.2Apparatus and equipment.Either the drum and shoe type of stroking apparatus (see Figure 1 of SA E Standard J1703b) except using only three sets of drum and shoe as-semblies, or the stroking fixture type apparatus as shown in Figure 2 of SAE J1703Nov83, with the components ar-ranged as shown in Figure 1 of SA E J1703Nov83. The following components are required. (a) Brake assemblies. With the drum and shoe apparatus: three drum and shoe assembly units (SAE RM –29a) con-sisting of three forward brake shoes and three reverse brake shoes with lin-ings and three front wheel brake drum assemblies with assembly component

49 CFR Ch. V (10–1–02 Edition)§571.116

parts. With stroking fixture type appa-ratus: three fixture units including ap-propriate adapter mounting plates to hold brake wheel cylinder assemblies. (b) Braking pressure actuation mecha-nism. A n actuating mechanism for ap-plying a force to the master cylinder pushrod without side thrust. The amount of force applied by the actu-ating mechanism shall be adjustable and capable of applying sufficient thrust to the master cylinder to create

a pressure of at least 6895 kPa (1,000 p.s.i.) in the simulated brake system. A hydraulic gage or pressure recorder, having a range of at least 0 to 6895 kPa (0 to 1,000 p.s.i), shall be installed be-tween the master cylinder and the brake assemblies and shall be provided with a shutoff valve and with a bleed-ing valve for removing air from the connecting tubing. The actuating mechanism shall be designed to permit adjustable stroking rates of approxi-mately 1,000 strokes per hour. Use a mechanical or electrical counter to record the total number of strokes.

(c) Heated air bath cabinet. A n insu-lated cabinet or oven having sufficient capacity to house the three mounted brake assemblies or stroking fixture assemblies, master cylinder, and nec-essary connections. A thermostatically controlled heating system is required to maintain a temperature of 70°±5 °C (158°±9 °F) or 120°±5 °C (248°±9 °F). Heat-ers shall be shielded to prevent direct radiation to wheel or master cylinder.

(d) Master cylinder (MC) assembly (SAE RM–15a). One cast iron housing hydrau-

lic brake system cylinder having a di-ameter of approximately 28 mm. (11?8 inch) and fitted for a filler cap and standpipe (see S6.13.2(e)). The MC pis-ton shall be made from SA E CA360 copperbase alloy (half hard). A new MC assembly is required for each test.

(e) Filler cap and standpipe. MC filler cap provided with a glass or uncoated steel standpipe. Standpipe must pro-vide adequate volume for thermal ex-pansion, yet permit measurement and adjustment of the fluid level in the sys-tem to ±3 ml. Cap and standpipe may be cleaned and reused.

(f) Wheel cylinder (WC) assemblies (SAE RM–14a). Three unused cast iron hous-ing straight bore hydraulic brake WC assemblies having diameters of ap-proximately 28 mm (11?8inch) for each test. Pistons shall be made from unanodized SA E A A 2024 aluminum alloy.

(g) Micrometer. Same as S6.6.2(d).

S6.13.3Materials.

(a) Standard SBR brake cups. Six standard SAE SBR wheel cylinder test cups, one primary MC test cup, and one secondary MC test cup, all as described in S7.6, for each test.

(b) Steel tubing. Double wall steel tub-ing meeting SA E specification J527. A complete replacement of tubing is es-sential when visual inspection indi-cates any corrosion or deposits on inner surface of tubing. Tubing from master cylinder to one wheel cylinder shall be replaced for each test (minimum length .9 m.) Uniformity in tubing size is required between master cylinder and wheel cylinder. The stand-ard master cylinder has two outlets for tubing, both of which must be used.

S6.13.4Preparation of test apparatus. (a) Wheel cylinder assemblies. Use un-used wheel cylinder assemblies. Dis-assemble cylinders and discard cups. Clean all metal parts with ethanol (isopropanol when testing DOT 5 fluids). Inspect the working surfaces of all metal parts for scoring, galling, or pitting and cylinder bore roughness, and discard all defective parts. Remove any stains on cylinder walls with cro-cus cloth and ethanol (isopropanol when testing DOT 5 fluids). If stains cannot be removed, discard the cyl-inder. Measure the internal diameter of each cylinder at a location approxi-mately 19 mm. (0.75 inch) from each end of the cylinder bore, taking meas-urements in line with the hydraulic inlet opening and at right angles to this centerline. Discard the cylinder if any of these four readings exceeds the maximum or minimum limits of 28.66 to 28.60 mm. (1.128 to 1.126 inch). Meas-ure the outside diameter of each piston at two points approximately 90° apart. Discard any piston if either reading ex-ceeds the maximum or minimum limits of 28.55 to 28.52 mm. (1.124 to 1.123 inch). Select parts to insure that the clear-ance between each piston and mating cylinder is within 0.08 to 0.13 mm. (0.003 to 0.005 inch). Use unused SBR cups. To remove dirt and debris, rinse the cups in 90 percent ethyl alcohol for not more

Nat’l Highway Traffic Safety Admin., DOT§571.116

than 30 seconds and wipe dry with a

clean lint-free cloth. Discard any cups

showing defects such as cuts, molding

flaws, or blisters. Measure the lip and

base diameters of all cups with an opti-

cal comparator or micrometer to the

nearest 0.02 mm. (0.001 inch) along the

centerline of the SA E and rubber-type

identifications and at right angles to

this centerline. Determine base diame-

ter measurements at least 0.4 mm.

(0.015 inch) above the bottom edge and

parallel to the base of the cup. Discard

any cup if the two measured lip or base

diameters differ by more than 0.08 mm.

(0.003 inch). A verage the lip and base

diameters of each cup. Determine the

hardness of all cups according to S7.4.

Dip the rubber and metal parts of

wheel cylinders, except housing and

rubber boots, in the fluid to be tested

and install them in accordance with

the manufacturer’s instructions. Manu-

ally stroke the cylinders to insure that

they operate easily. Install cylinders in

the simulated brake system.

(b) Master cylinder assembly. Use an

unused master cylinder and unused

standard SBR primary and secondary

MC cups which have been inspected,

measured and cleaned in the manner

specified in S6.13.4(a), omitting hard-

ness of the secondary MC cup. How-

ever, prior to determining the lip and

base diameters of the secondary cup,

dip the cup in test brake fluid, assem-

ble on the MC piston, and maintain the

assembly in a vertical position at 23°±5

°C. (73.4°±9 °F.) for at least 12 hours. In-spect the relief and supply ports of the

master cylinder; discard the cylinder if

ports have burrs or wire edges. Measure

the internal diameter of the cylinder at

two locations (approximately midway

between the relief and supply ports and

approximately 19 mm. (0.75 inch) be-

yond the relief port toward the bottom

or discharge end of the bore), taking

measurements at each location on the

vertical and horizontal centerline of

the bore. Discard the cylinder if any

reading exceeds the maximum or min-

imum limits of 28.65 to 28.57 mm. (1.128

to 1.125 inch). Measure the outside di-

ameter of each end of the master cyl-

inder piston at two points approxi-

mately 90° apart. Discard the piston if

any of these four readings exceed the

maximum or minimum limits of 28.55 to 28.52 mm. (1.124 to 1.123 inch). Dip the rubber and metal parts of the mas-ter cylinder, except the housing and push rod-boot assembly, in the brake fluid and install in accordance with manufacturer’s instructions. Manually stroke the master cylinder to insure that it operates easily. Install the mas-ter cylinder in the simulated brake system.

(1) When using a shoe and drum type apparatus, adjust the brake shoe toe clearances to 1.0±0.1 mm (0.040±0.004 inch). Fill the system with brake fluid, bleeding all wheel cylinders and the pressure gage to remove entrapped air. Operate the actuator manually to apply a pressure greater than the re-quired operating pressure and inspect the system for leaks. A djust the actu-ator and/or pressure relief valve to ob-tain a pressure of 6895 kPa±345 kPa (1,000±50 p.s.i.). A smooth pressure stroke pattern is required when using a shoe and drum type apparatus. The pressure is relatively low during the first part of the stroke and then builds up smoothly to the maximum stroking pressure at the end of the stroke, to permit the primary cup to pass the compensating hole at a relatively low pressure. Using stroking fixtures, ad-just the actuator and/or pressure relief valve to obtain a pressure of 6895 kPa±345 kPa (1,000±50 p.s.i.).

(2) A djust the stroking rate to 1,000±100 strokes per hour. Record the fluid level in the master cylinder standpipe.

S6.13.5Procedure. Operate the sys-tem for 16,000±1,000 cycles at 23°±5 °C.

(73.4°±9 °F.). Repair any leakage, read-just the brake shoe clearances, and add fluid to the master cylinder standpipe to bring to the level originally re-corded, if necessary. Start the test again and raise the temperature of the cabinet within 6±2 hours to 120°±5 °C. (248°±9 °F.). During the test observe op-eration of wheel cylinders for improper functioning and record the amount of fluid required to replenish any loss, at intervals of 24,000 strokes. Stop the test at the end of 85,000 total recorded strokes. These totals shall include the number of strokes during operation at 23°±5 °C. (73.4°±9 °F.) and the number of

城市道路交通设计规范

中华人民共和国国家标准城市道路交通规划设计规范 Code for transport planning on urban road GB 50220-95 主编单位:中华人民共和国建设部批准部门:中华人民共和国建设部施行日期:1995年9月1日关于发布国家标准《城市道路交通规划设计规范》的通知建标［1994］808号根据国家计委计综（1986）250号文的要求，由建设部会同有关部门共同制订的《城市道路交通规划设计规范》已经有关部门会审，先批准《城市道路交通规划设计规范》GB50220-95为强制性国家标准，自1995年9月1日起施行。本标准由建设部负责管理，具体解释等工作由上海同济大学负责，出版发行由建设部标准定额研究所负责组织。中华人民共和国建设部 1995年1月14日

城市道路交通规划设计规范第一章总则第一条为了加强城市道路管理，保障城市道路完好，充分发挥城市道路功能，促进城市经济和社会发展，制定本条例。第二条本条例所称城市道路，是指城市供车辆、行人通行的，具备一定技术条件的道路、桥梁及其附属设施。第三条本条例适用于城市道路规划、建设、养护、维修和路政管理。第四条城市道路管理实行统一规划、配套建设、协调发展和建设、养护、管理并重的原则。第五条国家鼓励和支持城市道路科学技术研究，推广先进技术，提高城市道路管理的科学技术水平。第六条国务院建设行政主管部门主管全国城市道路管理工作。省、自治区人民政府城市建设行政主管部门主管本行政区域内的城市道路管理工作。县级以上城市人民政府市政工程行政主管部门主管本行政区域内的城市道路管理工作。 1 总则 1.0.1 为了科学、合理地进行城市道路交通规划设计，优化城市用地布局，提高城市的运转效能，提供安全、高效、经济、舒适和低公害的交通条件，制定本规范。 1.0.2 本规范适用于全国各类城市的城市道路交通规划设计。 1.0.3 城市道路交通规划应以市区内的交通规划为主，处理好市际交通与市内交通的衔接、市域范围内的城镇与中心城市的交通联系。 1.0.4 城市道路交通规划必须以城市总体规划为基础，满足土地使用对交通运输的需求，发挥城市道路交通对土地开发强度的促进和制约作用。 1.0.5 城市道路交通规划应包括城市道路交通发展战略规划和城市道路交通综合网络规划两个组成部分。 1.0.6 城市道路交通发展战略应包括下列内容： 1.0.6.1 确定交通发展目标和水平； 1.0.6.2 确定城市交通方式和交通结构； 1.0.6.3 确定城市道路交通综合网络布局、城市对外交通和市内的客货运设施的选址和用地规模；

城市道路工程设计规范(2016年版)

4．按海绵城市建设的要求补充道路雨水低影响开发设计的原则和要求。 5．按《室外排水设计规范》GB50014修订的内容，调整了道路排水采用的暴雨强度的重现期规定。 6．补充了低影响开发设施内植物的种植要求。本规范中下划线为修改的内容，用黑体字表示的条文为强制性条文，必须严格执行。本规范由住房和城乡建设部负责管理和对强制性条文的解释，由北京市市政工程设计研究总院有限公司负责具体技术内容的解释。执行过程中如有意见和建议，请寄送北京市市政工程设计研究总院有限公司（地址：北京市海淀区西直门北大街32号3号楼（市政总院大厦），邮政编码：100082）本次局部修订的主编单位、参编单位、主要起草人员、主要审查人员：主编单位：北京市市政工程设计研究总院有限公司参编单位：天津市市政工程设计研究院重庆市设计院主要起草人员：和坤玲王晓华杨斌盛国荣

美国制动液标准 FMVSS-116-2002 DOT

49 CFR Ch. V (10–1–02 Edition)§571.115 §571.115[Reserved] §571.116Standard No. 116; Motor ve-hicle brake fluids. S1. Scope. This standard specifies re-quirements for fluids for use in hydrau-lic brake systems of motor vehicles, containers for these fluids, and labeling of the containers. S2. Purpose. The purpose of this standard is to reduce failures in the hy-draulic braking systems of motor vehi-cles which may occur because of the manufacture or use of improper or con-taminated fluid. S3. Application. This standard applies to all fluid for use in hydraulic brake systems of motor vehicles. In addition, S5.3 applies to passenger cars, multi-purpose passenger vehicles, trucks, buses, trailers, and motorcycles. S4. Definitions. Blister means a cavity or sac on the surface of a brake cup. Brake fluid means a liquid designed for use in a motor vehicle hydraulic brake system in which it will contact elastomeric components made of sty-rene and butadiene rubber (SBR), ethylene and propylene rubber (EPR), polychloroprene (CR) brake hose inner tube stock or natural rubber (NR). Chipping means a condition in which small pieces are missing from the outer surface of a brake cup. Duplicate samples means two samples of brake fluid taken from a single packaged lot and tested simulta-neously. Hydraulic system mineral oil means a mineral-oil-based fluid designed for use in motor vehicle hydraulic brake sys-tems in which the fluid is not in con-tact with components made of SBR, EPR or NR. Packager means any person who fills containers with brake fluid that are subsequently distributed for retail sale. Packaged lot is that quantity of brake fluid shipped by the manufacturer to the packager in a single container, or that quantity of brake fluid manufac-tured by a single plant run of 24 hours or less, through the same processing equipment and with no change in in-gredients. Scuffing means a visible erosion of a portion of the outer surface of a brake cup. A silicone base brake fluid (SBBF) is a brake fluid which consists of not less than 70 percent by weight of a diorgano polysiloxane. Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface, such that a visible black streak is produced when the cup, with a 500±10 gram deadweight on it, is drawn base down over a sheet of white bond paper placed on a firm flat sur-face. Stickiness means a condition on the surface of a brake cup such that fibers will be pulled from a wad of U.S.P. ab-sorbent cotton when it is drawn across the surface. S5. Requirements. This section speci-fies performance requirements for DOT 3, DOT 4 and DOT 5 brake fluids; re-quirements for brake fluid certifi-cation; and requirements for container sealing, labeling and color coding for brake fluids and hydraulic system min-eral oils. Where a range of tolerances is specified, the brake fluid shall meet the requirements at all points within the range. S5.1Brake fluid. When tested in ac-cordance with S6, brake fluids shall meet the following requirements: S5.1.1Equilibrium reflux boiling point (ERBP). When brake fluid is tested ac-cording to S6.1, the ERBP shall not be less than the following value for the grade indicated: (a) DOT 3: 205 °C. (401 °F.). (b) DOT 4: 230 °C. (446 °F.). (c) DOT 5: 260 °C. (500 °F.). S5.1.2Wet ERBP. When brake fluid is tested according to S6.2, the wet ERBP shall not be less than the fol-lowing value for the grade indicated: (a) DOT 3: 140 °C. (284 °F.). (b) DOT 4: 155 °C. (311 °F.). (c) DOT 5: 1 180 °C. (356 °F.). S5.1.3. Kinematic viscosities. When brake fluid is tested according to S6.3, the kinematic viscosities in square millimeters per second at stated tem-peratures shall be neither less than 1.5 mm2/s at 100 °C. (212 °F.) nor more than the following maximum value for the grade indicated: (a) DOT 3: 1,500 mm2/s at minus 40 °C. (minus 40 °F.). (b) DOT 4: 1,800 mm2/s at minus 40 °C. (minus 40 °F.).

城市道路工程设计规范(2016年版)

城市道路工程设计规范 C ode f or d esign of u rban r oad e ngineering （2016年版） 2012-01-11发布2012-05-01实施中华人民共和国住房和城乡建设部发布修订说明本次局部修订是根据住房和城乡建设部《关于印发2016年工程建设标准规范制订、修订计划的通知》（建标函[2015]274号）的要求，由北京市市政工程设计研究总院有限公司会同有关单位对《城市道路工程设计规范》CJJ37-2012进行修订而成。本次局部修订依据海绵城市建设对城市道路提出的相关要求，对原有条文中道路分隔带及绿化带宽度、道路横坡坡向、路缘石形式、道路路面以及绿化带入渗及调蓄要求、道路雨水排除原则等相应修改或补充规定。本次局部修订条文合计9条，修订的主要技术内容是：1．补充了需要在道路绿化带或分隔带中设置低影响开发设施时，绿化带或分隔带的宽度要求，以及各种设施间的设计要求。 2．增加立缘石的类型和布置型式。 3．细化了道路横坡的坡向规定。 4．按海绵城市建设的要求补充道路雨水低影响开发设计的原则和要求。 5．按《室外排水设计规范》GB50014修订的内容，调整了道路排水采用的暴雨强度的重现期规定。 6．补充了低影响开发设施内植物的种植要求。本规范中下划线为修改的内容，用黑体字表示的条文为强制性条文，必须严格执行。本规范由住房和城乡建设部负责管理和对强制性条文的解释，由北京市市政工程设计研究总院有限公司负责具体技术内容的解释。执行过程中如有意见和建议，请寄送北京市市政工程设计研究总院有限公司（地址：北京市海淀区西直门北大街32号3号楼（市政总院大厦），邮政编码：100082）本次局部修订的主编单位、参编单位、主要起草人员、主要审查人员：主编单位：北京市市政工程设计研究总院有限公司参编单位：天津市市政工程设计研究院重庆市设计院主要起草人员：和坤玲王晓华杨斌盛国荣审查人员：张辰包琦玮李俊奇赵锂白伟岚任心欣 5 横断面

制动液试验方法)

科威特标准802: 2000 海湾标准595: 1995 公路汽车制动液试验方法科威特国家工业管理局

公路汽车制动液试验方法 ICS: GSMO理事会批准日期: 正式公报公布日期: 本标准实施日期: 07-05-1416H (1995年10月1日) 17-06-1416H (1995年11月10日) 17-12-1416H (1996年5月4日)

公路汽车制动液试验方法 1. 应用的范围和领域本标准是有关装有天然或合成橡胶(等苯乙烯丁二烯橡胶)制成的橡胶帽和阀门座的制动系统的公路汽车的非石油基制动液的试验方法。 2. 补充参考资料 2.1 GS 594/1995“公路汽车制动液” 2.2 GS______/______“石油产品运动粘度和动力粘度的测定” 2.3 GS 183/1994“测定橡胶的硬度, 单位: 国际橡胶硬度标度(IRHD)” 3. 目视检查制动液试样应进行目视检查其均匀性、透明度和有无悬浮的物质、灰尘和沉积物。容器上标有的信息也应检查, 确定其是否符合2.1所给出的海湾标准的要求。 4. 测定运动粘度运动粘度应按2.2给出的海湾标准测定。 5. 均衡回流沸腾点的测定 5.1 装置和仪表装置应包括下述零件如图(1)所示。

5.1.1 100毫升容积短颈圆底蒸馏水瓶, 有8-9毫米内直径的侧管装温度计。尺寸 19/38的地面上的玻璃连接架装在瓶的颈部。 5.1.2 温度计应具有下列特性: 测量温度到400℃ 刻度为1℃ 每10℃有数字指明度数长度: 413毫米浸入76毫米刻度误差不应超过1℃ 5.1.3 水冷凝器 5.1.4 能供给符合规定的热和回流率所要求热的热源。 5.2 程序 5.2.1 将60毫升应试验的制动液和3或4块多孔瓷制品放入瓶中, 将瓶子连在冷凝器上, 穿过侧管将温度计牢牢地插入距瓶底不到6毫米的地方, 将瓶子安装在一有石棉线的测量仪表上并用支架固定。 5.2.2 接通水冷凝器供热, 使液体10±2分钟回流, 回流速率不应超过5滴/秒。5.2.3 调节热流以获得1或2滴/秒的回流率, 经过5±2分钟。定时的和不变的均衡回流率保持在1-2滴/秒, 再经过2分钟作记录(最近一个摄氏刻度), 每30秒间隔取的4个温度读数平均值作为平衡回流沸腾点(ERBP)。

gbt10830-89汽车制动液使用技术条件

汽车制动液使用技术条件中华人民共和国国家标准GB10830-89 1主题内容与适用范围本标准规定了汽车制动液使用性能、技术内容及试验方法。本标准适用于汽车液压制动系制动液的使用条件。 2引用标准 GB265石油产品运动粘度测定法 GB531橡胶邵尔A型硬度测试方法 GB4016石油产品名词术语 GB5620. 1汽车和挂车制动名词术语及其定义制动系种类、组成、力学及现象 GB5620. 2汽车和挂车制动名词术语及其定义零部件 GB7304石油产品和润滑剂中和值测定方法GB7524汽车液压制动橡胶皮碗 ZB E39006汽车制动液平衡回流沸点试验方法 3术语、代号 3. 1术语 3. 1. 1 制动液brake fluide 汽车液压制动系所采用的非矿油型传递压力的工作介质。 3. 1. 2 湿沸点wet boiling point 在制动液的试样中按一定的方法增湿后测得的该溶液的平衡回流沸点。 3. 2代号 3. 2. 1 JG为汽车制动液使用技术条件标准的代号。 J、G分别为交通部、公安部两部汉语拼音字的第一个字母。 3. 2. 2 JG右下角的阿拉伯数字（0、1、2、3、4、5）为JG系列各级的序号。 4技术要求 JG系列汽车制动液使用技术条件分为JG、JG、JG、JG、JG、JG六级。 4 . 1各级制动液使用技术条件具体要求见表1。 4 . 2除了以上技术条件规定的项目以外，汽车制动液中的具体产品标准及其实验方法均应按国家标准或专业标准执行。 4 . 3各级制动液主要特性和推荐使用范围见表2。 4 . 4行驶于多坡道山间公路制动强度较高的车辆，所用制动液应具有良好的高温抗气阻性能。 5试验方法

汽车刹车油(制动液)常识及更换方法

汽车刹车油（制动液）常识及更换方法刹车油的选择很重要，关系到安全哦，所以一定要慎重选择质量有保障的，不要图便宜啊。刹车油DOT标准制订很苛刻，并非简单调配就能达到的。国内市场上很多低价劣质制动液都标明符合DOT3、DOT4标准，其实产品质量并不合格。专家建议：制动液二年/4万公里更换制动液具有吸水特性，长时间不更换会腐蚀制动系统，给行车带来隐患。制动液一般两年或者4万公里更换一次，根据具体车型不同，更换的制动液级别和容量也会不同。真正合格达标的制动液有几个特性：即在高温、严寒、高速、湿热等工况条件下保证灵活传递制动力；对刹车系统的金属和非金属材料没有腐蚀性；能够有效润滑刹车系统的运动部件，延长刹车分泵和皮碗的使用寿命。所以消费者选择合格的制动液产品非常重要。使用劣质制动液的危害很多，劣质的制动液平衡回流沸点不达标，这样的产品易产生气阻，造成刹车失灵；而且劣质的制动液运动粘度不合格，低温时粘度过大会使刹车迟缓，高温时粘度过低又导致润滑性差，零件磨损严重。所以消费者选购制动液时在三个方面要注意：一闻：闻气味。达标制动液闻起来是甜甜的味道，劣质制动液闻起来是甲醇的臭味，或者人工香精的味道。二试：试粘稠度。合格刹车油明显较水粘稠，看起来很像稀释后的蜂蜜，倒在玻璃板上扩散速度慢。劣质刹车油粘度和水一样稀，倒少量在玻璃板上扩散速度快，用手指蘸取也可以感觉到没有稠度。

三比较：比较价格，成本决定价格，价格决定质量。合格制动液原料主要来源于石油加工基本原料---环氧乙烷，由环氧乙烷聚合成多乙二醇单醚，目前环氧乙烷单体的价格为16000元/吨。导致合格制动液的材料成本较高。按正常生产成本判断，凡是800g每瓶市场零售价在18元/瓶以内的制动液，极大可能是不达标的产品，其中零售价在10元/800g左右的制动液更是100%为甲醇类劣质制动液产品。另外，如果您的车要求用级别是DOT4的，千万不要用DOT3的！反之，如果要求用DOT3的话，则可以用DOT4的代替，也就是高等级标准的已经代替了低等级的了。更换准备工作（捷达为例）： 1.最好是三个人操作：一个负责放油，一个负责踩刹车踏板，一个负责加新油。也可以两个人：一个负责放油，一个负责踩刹车和加油。 2.换油前可拔掉保险座上第20号保险，使刹车尾灯在踩制动踏板时不亮，延长灯泡寿命。换完了想着装回去。 3.比较正规的方法要准备一根长度为50cm，内径在6mm左右的透明软塑料管和一个有容量标记的透明塑料瓶。更换刹车油时将软管一头插在分泵放油口，另一头插在塑料瓶中，避免费油飞溅和观察更换量。 4.准备新刹车油1～2瓶，原厂标准包装为2L，一瓶就够，为了清洗的更干净，两瓶也行，可留做以后补充用，但下次更换刹车油时最好不再使用旧油。正常的制动系统不会泄漏刹车油，刹车油液面只会随刹车片逐渐磨薄而下降，CL型以后的捷达车没有刹车油液面位置传感器，

制动液的分类、品种和牌号

（1）国外制动液的规格标准。常用的进口制动液有DOT3、DOT4二种。DOT是美国汽车安全标准规定标称，其数字越大，级别越高。DOT3与DOT4的不同之处主要在于沸点不同，DOT4比DOT3更耐高温。制动液的性能指标见表 1。表 1 制动液性能指标沸点（平衡环流沸点）工作情况 DOT3 DOT4 干 205°C以上 230°C以上湿 140°C以上 155°C以上 DOT3和DOT4级制动液是非矿物油系，是以聚二醇为基础和乙二醇及乙二醇衍生物为主的醇醚型合成制动液，再加润滑剂、稀释剂、防锈剂、橡胶抑制剂等调合而成，也是各国汽车所用最普遍的一种制动液。这种常用的制动液吸湿性较强。制动系统虽然进不了水分，但制动液使用一段时间以后会吸收相当的水分。制动液中水分越多，沸点越低。为了保证行车安全，制动液应定期更换（一般2年需更换一次）。由于制动液会吸收水分，所以放置多年已开封的制动液不要再用。（2）国产制动液的品种、牌号和规格。国产制动液依据其平衡回流沸点，可分为JG0、JG1、JG2、JG3、JG4、JG5六个质量等级，序号越大平衡回流沸点越高，高温抗气阻性越好，行车制动安全性越高。目前国内还在使用的制动液按原料不同分类，有合成型、醇型和矿油型三种。按原石油部标准生产的合成型制动液有4603、4603-1和4604等牌号。4603和4603-1号合成制动液适用于各类载货汽车的制动系。4604则适合于高级轿车和各种汽车的制动系，醇型汽车制动液分为1号和3号两个牌号，它是以乙醇或丁醇及篦麻油为原料，其抗阻性和低温流动性达不到要求，行车安全性差，已被淘汰。矿油型制动液牌号有良好的润滑性，无腐蚀性，但对天然橡胶有溶胀作用。

城市道路市政道路工程设计深度规定

市政道路工程初步设计文件编制深度规定 1 设计说明书 1.1概述 1.1.1 道路地理位置图示出道路在地区交通网络中的关系及沿线主要建筑物的概略位置。 1.1.2设计依据设计委托书、工程可行性研究报告（方案设计）的批复意见、相关评审报告、规划、地形等相关资料。 1.1.3对可行性研究报告（方案设计）批复意见的执行情况。如技术标准、规模有重大变化，应予以论证并履行报批手续。 1.1.4采用的规范和标准 1.1.5测设经过及设计过程简述 1.1.6需要说明的其它事项 1.2 现状评价及沿线自然地理情况 1.1.1道路现状评价 1.2.2现状交通量及技术评价交通量、车辆组成、路口交通流量与流向特征及路口、路段饱和度等。 1.2.3沿线基本情况沿线（控制性）建筑、河流、铁路及地上、地下管线情况。 1.2.4水文地质、气象等自然条件如河流设计水位、流速、地下水位、气温、降雨、日照、蒸发量、主导风向、风速等。 1.2.5工程场地自然条件 1.3 工程概况 1.2.1工程地点、范围及规模 1.3.2建设期限、分期修建计划 1.3.3规划简况

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汽车怎么换刹车油刹车油又叫汽车制动液．早期的汽车采用机械式制动的鼓式刹车。随着液压技术的发展，安全可靠的液压制动刹车系统广泛在汽车上应用。汽车制动液（刹车油）就是用于汽车液压制动系统的液体。当司机踩刹车时，从脚踏板上踩下去的力量，由刹车总泵的活塞，通过刹车油传递能量到车轮各分泵，使摩擦片涨开，达到停止车辆前进的目的，当停止刹车时，返回弹簧拉回摩擦片到原来的位置。刹车油具有吸水特性，如果长时间不更换会腐蚀制动系统，给行车带来隐患。所以，一般情况下建议车主，两年或者4万公里更换一次刹车油。准备工作： 1.最好是三个人操作：一个负责放油，一个负责踩刹车踏板，一个负责加新油。也可以两个人：一个负责放油，一个负责踩刹车和加油。 2.换油前可拔掉保险座上刹车灯的保险，使刹车尾灯在踩制动踏板时不亮，延长灯泡寿命。换完了想着装回去。 3.比较正规的方法要准备一根长度为50cm，内径在6mm左右的透明软塑料管和一个有容量标记的透明塑料瓶。更换刹车油时将软管一头插在分泵放油口，另一头插在塑料瓶中，避免费油飞溅和观察更换量。 4.准备新刹车油1～2瓶，一般一瓶就够，为了清洗的更干净，两瓶也行，可留做以后补充用，但下次更换刹车油时最好不再使用旧油。正常的制动系统不会泄漏刹车油，刹车油液面只会随刹车片逐渐磨薄而下降， 5.10mm眼镜扳手一个。

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