MECHANICAL BRAKES
Page K-19
Repair and Service Manual
Read all of Section B and this section before attempting any procedure. Pay particular attention to all Notices, Cautions, Dangers and Warnings.
Do not apply the brake when removing the nut as the shoes
may not fully retract preventing removal of the brake drum.
Remove washer (4).
Slide the brake drum (5) from the axle shaft. If required,
tap the drum with a plastic faced hammer to loosen it
from the axle shaft or use drum puller (P/N 15947-G1).
Use care when raising the adjuster arm. Too much
force will damage the adjuster and require that both
wheel brake assemblies be replaced.
If the drum does not slide from the brake assembly, the
brake shoes must be retracted. Rotate the hub so that
the hole in the drum is in the six o’clock position which is
directly over the brake mechanism. Use a small straight
blade screwdriver to raise the adjuster arm
just above
the star wheel.
Loosen the star wheel to retract the brake shoes and
remove the brake drum.
Pay particular attention to the location of the inner brake drum
washer (6) inside the brake drum, which may be on the axle
shaft or attached to the rear of the drum hub. This washer must
be reinstalled when the brake is reassembled.
To install the brake drum, clean the axle shaft and the
splines on the brake drum to remove dirt, grease and
foreign matter. Apply a small amount of anti-seize com-
pound to the axle spline. Install the inner brake drum
washer (6) and slide the brake drum (5) into place.
Check to ensure the nose of drum hub is beyond the
end of the axle splines. If not, remove drum and install
one additional inner brake drum washer (total of 2) to
obtain required spacing.
Do not back off nut to install cotter pin.
Install the remaining hardware and tighten the nut to 80-
90 ft. lbs. (108 - 122 Nm) torque. Continue to tighten
until a new cotter pin can be installed through the castel-
lated nut and the hole in the axle. Maximum torque is
140 ft. lbs. (190 Nm).
Wheel Brake Service
Wheel brake service consists of disassembly, cleaning,
inspection, lubrication and re-assembly of the wheel
brake. Worn or damaged components must be replaced.
Wheel brake service is required periodically as a pre-
ventive maintenance measure (see Periodic Service
Schedule in Section A). The wear rate of brake shoes
and required service intervals will vary based on usage,
terrain and other conditions. It is recommended that
wheel brake service be performed periodically on a
sample of vehicles within the service fleet to establish
the most efficient and effective service interval.
Remove the brake drum as described in ‘Brake Drum
Removal and Installation’.
Wear eye protection and a mask when clean-
ing brake components. Do not use com-
pressed air to remove brake dust from brake
assembly.
Do NOT use a commercial brake cleaner unless the
entire brake has been disassembled.
Remove any accumulated brake dust with a brush.
Remove the brake shoes. “Brake Shoe and Adjuster
Replacement” on page J 20
Clean backing plate with a commercial brake cleaner.
Allow to dry completely.
It is important that the friction areas between the back-
ing plate and the brake shoes be lubricated. Be careful
not to allow lubricant to contact the braking portion of
the brake shoes or the friction surface of the brake
drum. Use only recommended lubricants.
Lubricate the backing plate friction points of the shoes
and moving anchor with Multi Purpose Grease (MPG)
lubricant (Ref Fig. 24).
Install the actuator components, adjuster components
and brake shoes. “Brake Shoe and Adjuster Replacement”
on page J 20 If the brake shoes and drum are not to be
replaced, sand the friction surfaces lightly with emery
cloth to remove any foreign material.
NOTICE
NOTICE
