Chevrolet 10 Series 1970, Service Manual

Page: 304 / 671

BRAKES 5-66
1 Lock Ring
6
Camshaft and Brake
11 Brake Shoe Return Spring
2 Spacer
Chamber Bracket
12 Guide Pin Washer
3 Slack Adjuster
7 Backing Plate 13 Guide Pin " C ” Washer
4 Camshaft Seal
8
Cam (integral with shaft) 14 Guide Pin
5 Camshaft Bushing 9 Cam Roller
15 Lock Ring
10 Brake Shoe
16 Anchor Pin
F ig . 108—Front W h e e l Brake A ssem bly (W agner)
Removal
1. R em ove a ir line and lamp socket.
2. Rem ove four instrum ent panel backing plate screw s
and rem ove backing plate fro m veh icle.
3. Separate gauge fro m backing plate by rem ovin g two
retaining screw s.
Testing Replacement Unit
The sim p lest way to test any dash p ressu re gauge is to
com pare it with a sp ecial test gauge that is known to be
accurate. By substituting one gauge fo r another at one
given point in the a ir brake system , this com parison can
be made.
Installation
1. Attach gauge to instrum ent panel backing plate using
o rig in a l s c re w s o r equivalent.
2. Mount backing p late-gau ge assem bly in instrum ent
panel.
3. R eplace lamp socket and gauge line.
4. Thoroughly check gauge connection fo r leakage.
PRESSURE PROTECTION VALVE (Fig. 1 13 )
A
p ressu re p rotection va lve is used in the system to
guard against a ir p ressu re loss. It functions to close the
a ir lines to horns, w ip ers, transm ission shift, d ifferen tia l
lock etc., when the pressu re in the main a ir system fa lls
below 65 psi.
Disassembly
1. Rem ove four screw s and separate the upper and
lo w e r bodies.
2. R em ove diaphragm, spring cap and spring.
Cleaning and Inspection
1. Wash a ll parts in cleaning fluid.
2. Inspect diaphragm fo r cuts and punctures. Some
indentation o f the diaphragm by the seat in the low er
body is norm al.
Assembly
1. P osition diaphragm, spring cap and spring on lo w er
body.
2. A lign upper body with lo w e r body, in sta ll four screw s
and secure.
CHEVROLET TRUCK SERVICE MANUAL