TESTING APPLICATION ADJUSTER OPERATION
Place the vehicle on a hoist with a helper in the
driver’s seat to apply the brakes. Remove the access
plug from the rear adjustment slot in each brake
support plate (Fig. 4) to provide access to the ad-
juster star wheel. Then, to eliminate the possibility
of maximum adjustment, where the adjuster does not
operate because the closest possible adjustment has
been reached. Back the star wheel off approximately
30 notches. It will be necessary to hold the adjuster
lever away from the star wheel to permit this adjust-
ment.
Spin the wheel and brake drum in the reverse di-
rection, and with a greater than normal force apply
the brakes suddenly. This sudden application of force
will cause the secondary brake shoe to leave the an-
chor. The wrap up effect will move the secondary
shoe, and the cable will pull the adjuster lever up.
Upon application of the brake pedal, the lever should
move upward, turning the star wheel. Thus, a defi-
nite rotation of the adjuster star wheel can be ob-
served if the automatic adjuster is working properly.
If one or more adjusters do not function properly, the
respective drum must be removed for adjuster servic-
ing.
BLEEDING BRAKE SYSTEM
CAUTION: For bleeding of the Anti-Lock brake hy-
draulic system. See the Anti-Lock Brake system
service procedures in this group which refers to the
particular Anti-Lock brake system being serviced.
PRESSURE BLEEDING
Before removing the master cylinder cover, wipe it
clean to prevent dirt and other foreign matter from
dropping into the master cylinder.
CAUTION: Use bleeder tank Special Tool C-3496-B
with adapter Special Tool C-4578 to pressurize the
system for bleeding.
Follow pressure bleeder manufacturer’s instruc-
tions, for use of pressure bleeding equipment.
When bleeding the brake system. Some air may be
trapped in the brake lines or valves far upstream. As
much as ten feet from the bleeder screw (Fig. 6).
Therefore, it is essential to have a fast flow of a large
volume of brake fluid when bleeding the brakes to
ensure all the air gets out.
The following wheel sequence for bleeding the
brake hydraulic system should be used to ensure ad-
equate removal of all trapped air from the hydraulic
system.
• Right rear wheel
• Left front wheel
• Left rear wheel
• Right front wheel
To bleed the brake system. Attach a clear plastic
hose to the bleeder screw starting at the right rear
wheel and feed the hose into a clear jar containing
fresh brake fluid (Fig. 7).
Next, open the bleeder screw at least one full turn
or more to obtain an adequate flow of brake fluid
(Fig. 8).
CAUTION: Just cracking the bleeder screw often re-
stricts fluid flow, and a slow, weak fluid discharge
will NOT get all the air out.
After 4 to 8 ounces of fluid has been bled through
the brake system at this wheel. And an air-free flow
is maintained in the clear plastic hose and jar, this
will indicate a good bleed.
Repeat the procedure at all the other remaining
bleeder screws. Then check the pedal for travel. If
pedal travel is excessive or has not been improved.
Enough fluid has not passed through the system to
Fig. 5 Brake Drum Adjustment With Tool C-3784
Fig. 6 Trapped Air in Brake Line
5 - 6
BRAKES
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