Chevrolet Light Duty Truck 1973, Service Manual

Page: 283 / 979

BRAKES 5 -1 7
Fig. 29-B rake Bleeder J-23518 and J-23709
G Model Shown
(fig. 29). Be sure to retorque the mounting
bolt after removing Tool J-23709.
Install Brake Bleeder Wrench J-21472 on caliper
bleeder valve nearest the master cylinder and install
one end of bleeder hose on bleeder valve.
NOTE: If the master cylinder is equipped
with bleeder valves, bleed these valves first,
proceed to the bleeder valve nearest the
master cylinder, then the next nearest and so
on until all valves have been bled and there
is no evidence of air in the system.
Pour a sufficient amount of brake fluid into a
transparent container to ensure that end of bleeder
hose will remain submerged during bleeding. Place
the loose end of bleeder hose into the container. Be
sure the hose end is submerged in the fluid.
Open bleeder valve by turning Tool J-21472
counterclockwise approximately 3/4 of a turn and
observe flow of fluid at end of bleeder hose.
NOTE: To assist the bleeding operation a
rawhide mallet may be used to tap the caliper
while fluid is flowing.
Close bleeder valve tight as soon as bubbles stop
and brake fluid flows in a solid stream from the
bleeder hose.
Remove brake bleeder wrench and bleeder hose
from bleeder valve.
Repeat Steps 3 through 7 on the remaining bleeder
valves.
Disconnect bleeder equipment from brake bleeder
adapter.
NOTE: The master cylinder on certain
models is tilted. When removing the bleeder
adapter on these models, place a clean dry
Fig. 3 0 -Bleeding Brakes with Tool J 21472
cloth below the cylinder to absorb any fluid
spillage as the cover is removed.
10. Remove bleeder adapter. Wipe all areas dry if fluid
was spilled during adapter removal.
11. Fill master cylinder reservoirs to within 1/4" of
reservoir rims as shown in Figure 31.
12. Install master cylinder diaphragm and cover.
CAUTION:
When installing the master cylinder
cover, the retaining bail should be slipped over
the lower cover bosses (fig. 32). Incorrect
installation could result in bail tension loss and
fluid leakage.
13. Test operation of brake pedal before moving the
vehicle.
Manual Bleeding
1. Clean all dirt from the top of the master cylinder
LIGHT DUTY TRUCK SERVICE MANUAL