Chevrolet 70 1969 Series, Shop Manual

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POWER BRAKE 5-28
.
2
3 4
6
1
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...................... ...........
'•'•''V-wV
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M i
9 5
8
1 Body 6 Adjusting Screw
2 Ball Seat
7 Stem
3 Ball Valve 8 Lock Nut
4 Exhaust Port 9 Spring Cage
5 Spring T 9.V3
Figure 35— Safety Valve
4. Valve disc should be perfectly sm ooth and free of rust
or corrosion. Replace if necessary.
5. C heck valve body and valve cap for cracks or worn or
dam aged threads.
Assembly
1. Insert washer, seat, disc, and spring in valve body.
2. Install identification washer on valve cap.
3. Install valve cap in valve body.
DOUBLE CH ECK VALVE
Disassembly
1. Rem ove two bolts and lock washers attaching valve
cover to body. Separate body and cover.
2. Remove O-ring from cover. Discard O-ring.
3. Remove shuttle valve and guide from body.
Cleaning and Inspection
1. Clean all m etal parts in a suitable solvent.
2. Exam ine all parts for corrosion, rust, deterioration,
cracks, wear, etc. Replace as necessary, with new
parts.
3. Check to m ake sure shuttle valve slides freely back
and forth in valve guide.
Assembly
1. Apply a thin coating of a m ulti-purpose grease
(N .L .G .I. num ber 1 with a rust inhibitor ingredient)
to inside of valve guide.
2. Place guide and shuttle valve in valve body.
3. Install new O-ring in cover and position cover on
body.
4. Install bolts and lock washers and tighten evenly and
firmly.
DOUBLE CHECK VALVE AND
STOP LIGHT SWITCH ASSEMBLY
Disassembly
1. Remove two bolts and lock washers attaching valve
cover to body. Separate body and cover.
2. Remove O-ring from cover. Discard O-ring.
3. Rem ove shuttle valve and valve guide from body.
4. Rem ove two screws and lock washers attaching stop
light switch cover to valve body.
NOTE: Remove screws carefully as spring will
cause cover to fly off if not held.
5. Remove cover, spring, piston, cover gasket, contact
strip, and O-ring diaphragm from valve body.
13 14
TY
T T
1 2 3 4 5
6
7
1 Body
2 Washer
3 Seat
4 Disc
5 Identification Washer
6 Spring
7 Cap
8 O-ring
9 Guide
10 Shuttle Valve
11 Gasket
12 Stop Light Switch Cover
13 Spring
14 Contact Strip
15 Piston
16 O-ring Diaphragm
T-4342
Figure 36— Check Valves
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHO P M A N U A L