Chevrolet Light Duty Truck 1973 Service Manual page 333

LUBRICATION
The power brake unit is lubricated at assembly and
needs no further lubrication other than maintaining
normal reservoir fluid level. The reservoir should be
filled as described in this section.
BLEEDING
The power system may be bled manually or with a
pressure bleeder as outlined in this section. Use only GM
Supreme 11 Brake Fluid or equivalent. Do not use the
power assist while bleeding. The engine should not be
POWER BRAKE UNIT
Removal
1. Remove all dirt from the exterior of the master
cylinder. Disconnect the brake lines from the two
master cylinder hydraulic outlets. Cover brake line
fittings to prevent dust and dirt from entering brake
lines.
2. Disconnect the vacuum hose from the vacuum
check valve on the front housing of the power head.
Plug vacuum hose to prevent dust and dirt from
entering hose.
3. Disconnect the power brake push rod from the
brake pedal.
4. Remove the four nuts (inside vehicle) from the
mounting studs which hold the power brake to the
dash panel.
C O M P O N E N T PART REPLACEMENT
running and the vacuum reserve should be reduced to
zero by applying the brake several times before starting
the bleeding procedure.
AIR CLEANER SERVICE
Servicing of the air cleaner is recommended and the
element replaced when restriction becomes severe
enough to affect power brake response. At any other
time, if cleaning of the filter is felt necessary, it should
be shaken free of dirt or washed in soap and water and
thoroughly dried.
5. Carry the power brake to a clean work area and
clean the exterior of the power brake prior to
disassembly (see the applicable portion of the
"Overhaul" manual for disassembly at the power
unit).
Installation
1. Mount power brake assembly to dash.
See "Caution" on Page 1 of t h i s
CAUTIO N:
s e c t i o n .
2. Connect power brake push rod to brake pedal.
3. Connect vacuum hose to vacuum check valve.
4. Connect brake lines to master cylinder outlets.
"
See Caution
CAUTIO N:
s e c t i o n .
5. Bleed brakes as necessary and fill fluid reservoirs to
within 1 /4" of top of the reservoirs.
BRAKES 5 -6 7
"
on Page 1 of t h i s
LIGHT DUTY TRUCK SERVICE MANUAL