Chevrolet 70 1969 Series, Shop Manual

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POWER BRAKE 5-13
L .
9 1011 12 13 14 15 16 17 18
■ ~7
/
1 Bolt
7 O-Ring
2 Valve Body
8 Valve Cover
3 O-Ring
9 Exhaust Check
4 Piston Return Spring
10 Bolt
5 Inlet and Exhaust Valve Seat
11 Exhaust Cover
6 Piston
12 Snap Ring
13 Valve Cap
14 O-Ring
15 O-Ring
16 Valve Return Spring
17 Spring Seat
18 Inlet and Exhaust Valve
Figure 9 — R e lay V a lv e C o m p o n e n ts (Piston Type)
5. Turn valve over and install exhaust valve in valve
body.
6. Install exhaust valve return spring.
7. Install O-ring on valve cage and install cage in valve
body.
8. C om press exhaust valve spring and install snap ring.
9. Place pedal bracket in position and secure with four
screws.
10. Install stop screw and lock nut.
11. Install pedal lever, lever pin and cotter pin.
RELAY VALVE
DISASSEMBLY— PISTON TYPE
( ALL CONVENTIONAL MODELS) ( Refer to Fig. 9)
1. Scribe m arks on cover and valve body to perm it pro­
per reassembly. Rem ove four bolts which fasten cover
to valve body.
2. Rem ove cover. Piston will rem ain inside cover. R e­
move piston return spring.
3. Rem ove piston and O-ring from cover. Use air pres­
sure if necessary.
4. Rem ove O-ring from piston.
5. R em ove inlet and exhaust valve seat.
6. Rem ove O-ring from valve body.
7. Rem ove two bolts which fasten exhaust cover to valve
body.
8. Rem ove exhaust cover and remove exhaust check
from cover.
9. Press inlet and exhaust valve assembly out of valve
body.
10. Disassemble inlet and exhaust valve:
a. Remove snap ring and separate valve cap, return
spring and spring seat from valve.
b. Remove O-rings from valve cap.
ASSEMBLY
1. Install O-rings in valve cap.
2. Assem ble inlet and exhaust valve; install spring seat,
return spring and valve cap on valve and secure with
snap ring.
3. Press inlet and exhaust valve in valve body.
4. Install exhaust check in exhaust cover and install
cover on valve body.
5. Install O-ring in valve body.
6. Install valve seat in piston.
7. Install O-ring on piston.
8. In stall piston assem b ly in cover.
9. Place piston return spring in valve body.
10. Place piston and cover assem bly on valve body (align
m arks m ade at disassembly), com press return spring
and secure cover to body with four bolts.
PRESSURE PROTECTION VALVE
DISASSEMBLY (Refer to Fig. 10)
1. Since this valve contains a heavy spring (65 psi) place
it in a vise before disassembly.
2. Rem ove four screws which fasten upper body to lower
body.
3. Open vise slowly until spring tension is com pletely re­
lieved.
4. Separate body halves and remove spring, diaphragm
and spring cap.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SH O P M A N U A L