Pontiac FIREBIRD 1972 Service Manual page 484

TANDEM DIAPHRAGM POWER BRAKE-MORAINE 5D-7
P
l
STON VALVE
-MODULATED VACUUM CHAMBERS
/
PRIMARY DIAPHRAGM
CONSTANT VACUUM
ATMOSPHERIC PRESSURE
DELCO MORAINE
Fig. 5D-5 Releasing Position
MINOR REPAIRS
BLEEDING BRAKES STOP LAMP SWITCH
Brakes should be bled in the same manner as standard See Section 5 for service.
brakes: Bleed with engine off and vacuum reserve dep-
leted. Hold off disc brake metering valve with tool J
23709. For information on bleeding brakes see Sections 5
and 5E.
MAJOR REPAIRS
MASTER CYLINDER ONLY POWER CYLINDER ONLY
REMOVE
Certain repair operations, such as replacement of master
cylinder internal parts, permit the master cylinder to be
removed by itself, leaving the power cylinder, pedal, and
brackets in the car.
1. Remove hydraulic connections from master cylinder,
pump fluid from cylinder into a container and dis-
pose of fluid. Cover openings at cylinder and pipes to
exclude dust, dirt, etc.
2. Remove master cylinder attaching nuts and remove
master cylinder from power section.
REMOVE
1. Remove vacuum check valve.
2. Remove master cylinder and position it away from
power cylinder.
CAUTION: Do not disconnect hydraulic fluid
lines; be careful not to bend or kink lines.
3. Remove clevis pin retainer at brake pedal.
4. Remove four power unit to dash attaching nuts.
5. Remove power cylinder.