Removal Procedure
- Block the wheels.
- Cage the rear air brake chambers. Refer to
Caging the Rear Air Brake Chamber
.
- Drain all air reservoirs. Refer to
Draining Reservoirs
in Air Brakes.
- Remove the retainer.
- Remove the clevis pin.
- Fully release the slack adjuster by turning the slack adjuster
counterclockwise. Continue the operation until the slack adjuster arm is free
from the clevis.
- Loosen the jam nut.
- Remove the clevis and the jam nut.
- Inspect the service brake chamber pushrod for damage.
Overhaul or replace the service brake chamber if damaged.
Installation Procedure
- Loosely assemble the jam
nut and the air brake chamber clevis to the service brake chamber pushrod.
- Adjust the clevis.
Turn the air brake chamber clevis clockwise in order to decrease the
distance and counterclockwise in order to increase the distance.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Measure the front
air brake chamber clevis to 72.0 mm (2.83 in) from the mounting
surface of the service brake chamber to the center of the air brake
chamber clevis pin mounting hole.
- Measure the rear air brake chamber clevis to 68.5 mm (2.69 in)
from the mounting surface of the spring brake chamber to the center of the
air brake chamber clevis pin mounting hole.
Tighten
• | Tighten the front air brake chamber clevis jam nut (type 16 service
air brake chamber) to 45 N·m (33 lb ft). |
• | Tighten the front air brake chamber clevis jam nut (types 20 and
24 service air brake chamber) to 78 N·m (57 lb ft). |
• | Tighten the rear air brake chamber clevis jam nut to 77 N·m
(56 lb ft). |
- Rotate the adjusting hex
of the slack adjuster clockwise.
Continue the operation until the arm hole of the slack adjuster lines
up with the clevis hole.
- Install the air brake
chamber clevis pin.
- Install the air brake chamber clevis pin cotter pin.
- Adjust the brakes. Refer to
Air Drum Brake Adjustment
.
- Start the engine.
- Charge the system to the air compressor governor valve cut-out
point.
- Stop the engine.
- Uncage the rear air brake chambers. Refer to
Caging the Rear Air Brake Chamber
.
- Check for the proper brake operation.
- Apply the parking brake.
- Remove the wheel blocks.