MOTOR TRUCK SERVICE MANUAL
BRAKES-AIR
Recommended Grease
grease or equivalent to NLGI #2 multipurpose grease is
A high temperature water-proof grease, IH 251 HE.P.
recommended for lubricating the brake actuating system.
The following greases meet all of these recommendations:
Texaco Thermotex EP f1
Shell Darina f1
Marathon 528 H.D.
Sunaplex t1 EP
Amdex f1 EP
Philube B t1
NOTE: Vehicles operating in extremely cold weather (below -400F) may require a grease conforming to MIL-G-25013C.
Replacing Air Chamber Diaphragm: The air chamber diaphragm and push rod boot may be serviced in either of two
ways-removing the complete chamber from the brake, or removing the clamp ring and pressure half only and leaving the
non-pressure half attached to the brake. The latter method is recommended but, since the wedge assembly is left inside
the tube, certain precautions must be taken to prevent the wedge assembly from being pulled out of position and
becoming misaligned with the plungers. The proper procedure is given under Servicing Air Chamber Diaphragm
TROUBLE SHOOTING GUIDE
If brakes are poor or do not apply- check system pressure at source and at brakes possible restriction or leak in brake
lines, valves, etc. brakes out of adjustment leaking diaphragm or wheel cylinder cup.
Uneven braking or lining wear-ruptured diaphragm wedge rod out of push rod socket rollers and cage out of plunger
socket corroded or frozen plungers brakes out of adjustment grease on lining glazed lining shoes installed backward
combination linings.
Automatic Adjusters not working-adjusting pawl installed backward pawl spring collapsed or missing bolt frozen in
adjusting sleeve detent damaged and allowing bolt to rotate with sleeve adjusting plunger in wrong position (should be at
leading end of shoe) double lip seals not installed correctly.
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