Chevrolet 1980 Light Duty Truck Repair Manual page 146

5-10 BRAKES
F ig . 5 - 6 B - R e m o v i n g R e a r S e a l
15. Place rear housing over front housing, and align
scribe marks.
16. R otate spanner w rench clockw ise until housings are
locked together. Bend tabs o f the four deep lances back to
their original position.
17. R em ove three nuts and lock washers securing rear
housing to spanner wrench.
18. R em ove H olding Fixture J-22805 from front
housing by rem oving two nuts and washers.
19. W et poppet valve with denatured alcohol and
assem ble in rear plate hub, sm all end first. W et poppet
retainer with denatured alcohol and assemble with shoulder
inside poppet. A ssem ble retainer, filters and silencer over
ridge on rod and return spring over ball end o f operating
valve rod. W et grom m et in valve plunger with denatured
alcohol and guide air valve rod into valve plunger. Tap end
o f operating valve rod w ith plastic hammer to lock ball in
grom m et. Press filters and silencers into hub and install
retainer on hub.
20. A ssem ble silencer in dust boot, wet dust boot
opening with denatured
operating valve rod and over flange o f rear housing.
Fig. 5-7B--Rear B earing and Rear Shell
O V E R H A U L M A N U A L
alcohol and assemble over
n e w
21. Install check valve and grom m et
. 22. A pply silicone lubricant to piston end o f hydraulic
push rod and insert in cavity in front plate. Twist rod to
elim inate air bubbles at reaction disc. A ssem ble seal over
push rod and press into recess in front housing.
Piston Rod G auging
1. Place the power head assem bly in a padded vise
D o not clamp tight.
(front housing up);
2. Remove the front housing seal to assure that no
vacuum is in the power head while gaging.
3. Insert the master cylinder piston rod, flat end first
into the piston rod retainer.
4. Press down on the master cylinder piston rod (with
approximately a 40-50 pound load) to be sure it is properly
seated.
5. Place Gage J-22647 over the piston rod in a position
which will allow the gage to be slipped to the left or right
without contacting the studs (fig. 5-12B).
6. The center section o f the gage has two levels. The
piston rod should always contact the longer section (lower
level) o f the gage. The piston rod should
Fig. 5 -9 B -S ea l P rotector J -2 2 7 3 3 Installed
,
never
contact the