Chevrolet 70 1969 Series, Shop Manual

Page: 633 / 913

POWER BRAKE 5-24
13 14 15 16 17
1 Mounting Nut
2 Lo ck W a sh e r
3 Cap Nut
4 Seal Ring
5 Inlet and Exhaust Valve Spring
6 Inlet and Exhaust Valve
7 Valve Body
8 Piston G ro m m et (Small)
9 Piston
10 Piston G r o m m et (Large)
11 Piston Spring (Small)
12 Piston Spring (Large)
13 Cover Plate
14 Retainer Ring
15 Exhaust Diaphragm
16 Diaphragm W a s h e r
17 C apscrew
Figure 2 8 — Inversion V a lv e A sse m b ly C o m p o n e n ts
IN VERSIO N VALVE
DISASSEMBLY (Figs. 27 and 28)
1. Remove cap nut with sealing ring, remove sealing ring
from cap nut.
2. T urn valve over and remove exhaust check valve dia­
phragm cap screw with lock washer, then diaphragm
washer and diaphragm .
3. W ith a pair of snap ring pliers, remove retainer ring.
4. Rem ove cover plate and two (2) piston springs.
5. Remove piston with grom m ets.
6. Rem ove piston grom m ets.
CLEANING AND INSPECTION
W ash all m etal parts in a good cleaning solvent. R u b ­
ber parts should be wiped clean. Inspect all parts for ex­
cessive wear or deterioration. C heck springs for cracks,
corrosion, or distortion. Inspect piston and its exhaust
seat, body bores and inlet valve seat for nicks or burrs.
Replace all parts not considered serviceable during these
inspections.
ASSEMBLY (Figs. 27 and 28)
Before assembling the valve, lubricate the piston, g rom ­
mets and body bores with barium base grease (or equiva­
lent).
1. Install piston grom m ets on piston.
2. Install piston with grom m ets in valve body.
3. Position piston springs, cover plate and retainer ring
in the valve body in that order.
4. Press the cover and retainer dow n and with a pair of
snap ring pliers and snap the ring into the body
groove.
5. Install diaphragm and diaphragm washer, then secure
with cap screw.
6. T urn inversion valve over and position inlet and ex­
haust valve in its bore.
7. Place spring down over inlet valve.
8. Install sealing ring on cap nut, install cap nut with
sealing ring and tighten securely.
9. M ounting nut and lock w asher are installed when
valve is m ounted on vehicle.
Q U ICK RELEASE VALVE
DISASSEMBLY (Fig. 29)
Rem ove four screws attaching body to cover. Separate
cover and body, rem ove diaphragm , and remove O-ring
from groove in cover.
CLEANING AND INSPECTION
Clean body and cover thoroughly. E xam ine diaphragm
for signs of cracking, wear, or dam age. E xam ine lower
face of diaphragm which contacts diaphragm seat on body
for signs of pitting or excessive grooving. Replace dia­
phragm if these conditions are found.
E xam ine O-ring seal. Replace with new seal if there is
any evidence of deterioration. M ak e sure seal ring groove
in cover is thoroughly cleaned.
ASSEMBLY (Fig. 29)
Install O-ring seal in groove in cover. Position dia­
phragm in body, install cover on body, and install four
body-to-cover screws; then tighten screws firmly.
SYN CH RO VALVE
DISASSEMBLY (Figs. 30 and 31)
1. Rem ove valve cap nut. Rem ove valve stop grom m et
from nut and discard.
2. Rem ove piston assem bly from valve body. Remove
piston grom m et and valve g ro m m et from piston and
discard.
3. Rem ove piston spring from valve body.
4. Remove valve cap. Remove valve cap grom m et from
valve cap and discard.
5. Rem ove valve stop, valve spring and valve.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHO P M A N U A L