B
36
Repair and Service Manual
BRAKES
Read all of SAFETY and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
699322
Wheel Brake Inspection
Wear a dust mask and eye protec-
tion whenever working on wheel
brakes. Do not use pressurized air
to blow dust from brake assemblies. Replace both
brake shoes on both wheels if one or more shoes
are worn below .06” (1.5mm) thickness at any point.
Do NOT touch any of the wheel
brake mechanism except as
instructed.
Do NOT use a commercial brake cleaner unless the
entire brake has been disassembled.
1. Remove the brake drums.
Do not disturb adjuster mechanisms. Remove excess
dust and dirt from the drum with a brush.
The drum must not be turned to
“true” a worn friction surface. Turn-
ing will make the drum too thin
causing drum failure and a loss of brakes which
could cause severe injury or death.
2. Inspect the brake drum.
Look for a blue coloration or blistered paint that would
indicate that it has overheated. Check for evidence of
scoring. Check for excessive wear indicated by the
friction surface being significantly worn and leaving a
ledge of unworn drum. Inspect the splines for galling,
wear and corrosion. If any of these problems are
found, the drum must be replaced.
3. Remove any accumulated brake dust from the wheel
brake assembly with a brush.
4. Visually inspect the axle seal for oil leakage and the
condition of the thrust washer. If oil is present, see
REAR AXLE section.
5. Verify the inner brake drum washer is present and
check its condition. Replace if damaged or missing.
If one wheel brake assembly
requires replacement, the second
must also be replaced.
Use care when handling the
adjuster arm. Too much force will
damage the adjuster and require
that both wheel brake assemblies be replaced.
6. Visually check the condition and operation of the
adjuster mechanism.
Inspect the brake lever for damage or wear. Test the
adjuster function as follows:
Push the front brake shoe in the direction of the rear
of the vehicle and hold in position.
Operate the brake lever.
Observe the brake adjuster arm and note if the arm
engages the star wheel and attempts to rotate it (Fig-
ure 14).
Figure 14 Adjuster Mechanism
If the adjuster arm
engages and turns
the star
wheel, proceed. If the arm
fails to engage
the star
wheel, it has been damaged and both wheel brake
assemblies must be replaced.
If the adjuster arm engages the star wheel but
fails to
rotate it
, the adjuster assemblies must be replaced
with new color-coded adjusters. Note the location of
the two Teflon coated washers (Figure 21).
7. Check the condition and operation of the moving
anchor assembly (Figure 21).
Operate the brake lever to check for free motion. The
adjuster assembly and brake lever should move
smoothly from front to back on the backing plate. If
the moving anchor assembly is damaged or binds
against the backing plate, replace both of the wheel
brake assemblies.
A backing plate assembly that
shows any indication of galling or
gouging is not repairable and must
be replaced with a new wheel brake assembly.
Always replace wheel brake assemblies in pairs.
8. Inspect the backing plate.
Inspect for gouges, galling or other damage, particu-
larly where the backing plate is contacted by the
brake shoes and by the moving anchor assembly.
Replace both backing plates if any gouges or galling
is found.
9. Measure the brake shoe thickness.
Measure at the most worn area. Brake shoe thick-
ness must never be less than .06" (1.5 mm) at any
point on the shoe. It is normal for the shoes to show
more wear at the leading and trailing edges (Figure
15). If the brake shoe thickness is approaching .06"
(1.5 mm), it is recommended that the shoes be
replaced. It is recommended that the brake shoe
Brake Adjuster
Arm
Adjusting
Screw
Wheel Brake
Lever
Star
Wheel
