PREVENTIVE MAINTENANCE BRAKE SYSTEM
Regional Haul
(R05/10) Y53-6033 – 183 –
• Do not use moly-disulfide loaded grease or oil (they
may shorten the service life of the slack adjuster).
• Do not use pressure-release grease fittings when
lubricating the slack adjuster.
Checks and Adjustments
All vehicle operators should check the brakes regularly.
Always adjust the brakes when they are cool.
• Park the vehicle on a level surface and block the
wheels before attempting any brake checks or adjust-
ments.
Brake Linings
WARNING! Do not use brake linings with a
thickness below the specified minimum. Such
linings will have lining rivets exposed that can
damage the brake drum and reduce brake effi-
ciency, which could cause death , personal
injury or system failure.
• Brake linings should be inspected for wear by a quali-
fied mechanic at an Authorized Service Center. See
Table 2, “Maintenance Schedule,” Page 152. In
severe service applications inspect the linings more
frequently.
Automatic Slack Adjusters
Your Regional Haul vehicle is equipped with automatic
brake (slack) adjusters.
Periodically, brake adjustment should be checked using
the following procedure:
1. Check brakes when the temperature of the service
brake linings are cool and the system air pressure is
at 100 psi (690 kPa) minimum.
2. Release the parking brakes to allow the slack adjust-
ers to retract.
3. Measure the retracted pushrod length from the face of
the brake chamber to the center of the pushrod pin.
4. Apply 80 to 90 psi brake application and measure the
same distance.
5. The difference is the pushrod travel distance (applied
stroke).
Verify that the result is within the correct range (see Table
4, ”Brake Adjuster Stroke”). Correctly installed and func-
tioning brakes (auto slack) will produce the strokes listed
for each chamber type.
