Buick LeSabre 1965 Service Manual page 552

9 - 3 0 POWER BRAKES
BRAKES
Pigure 9-20—Power Brake Unit
Positioned in a Vise
2. Remove retainer and special
washer from brake pedal pin and
disengage push rod eye.
3. Remove four nuts h o l d i n g
power brake unit to dash.
4. Disconnect vacuum hose from
power brake unit.
5. Remove power brake unit from
car, while being careful not to
drip brake fluid on exterior paint.
6. Remove filler cap and position
unit so that brake fluid will drain
out. Pump push rod by hand for
full interior drainage. Discard
old fluid. Install filler cap and
cover master cylinder outlet with
tape to exclude dirt. Clean all
loose dirt from outside of unit
before disassembling.
9 - 1 7 DISASSEMBLY OF
POWER BRAKE
UNIT
a. Disassembly of Overall
Unit & Front
Housing Group
1. Place the power brake assem-
bly in a vise or fixture with the
push rod up. Pump the push rod
three or four times to empty the
master cylinder of fluid.
NOTE: Scribe a mark on the top
center of the front and rear hous~
ings in line with master cylinder
reservoir cover to facilitate re-
assembly.
2. With the master cylinder res-
ervoir unit firmly clasped in a
vise, rotate the housings counter-
clockwise into the unlocked posi-
tion. Use p r y b a r s to assist
removal as shown in Figure 9-20.
NOTE: Loosen housing carefully
as it is heavily spring-loaded.
3. Lift the power piston assembly
and rear housing from the unit.
4. Remove rubber boot and si-
lencer from push rod.
5. Remove the power piston re-
turn spring f r o m t h e f r o n t
housing.
6. Reposition the master cylinder
assembly in the vise to facilitate
removal of the front housing from
the master cylinder. Remove the
two nuts and lock washers from
the studs. Remove the master
cylinder from the studs and lay
aside.
NOTE: For master cylinder dis-
assembly and reassembly, see
Section 9-C.
REACTION
BUMPER
REACTION
PLATE
REACTION
RETAINER
SUPPORT—i
PLATE
RUBBER
DIAPHRAGM
" O " RING
\
A I R - y
FILTER /
MASTER CYLINDER
PUSH ROD
\J
SNAP RING
AIR VALVE SPRING
\V\ \ RETAINER
\ \ i — A I R VALVE SPRING
" O " RINGS \ _
R E A C T
, o N
LOCK RING LEVERS
AIR
SILENCER
PUSH ROD, AIR VALVE,
& FLOATING CONTROL
VALVE ASSEMBLY
Figure 9-21— Power Piston Assembly - Exploded View