Chevrolet 70 1969 Series, Shop Manual

Page: 366 / 913

AIR COMPRESSORS AND GOVERNORS 6T-5
then fill cooling system.
5. Adjust governor as directed later.
IN S T A L L A T IO N (G EAR DRIVEN)
1. Before installing compressor, examine hub
on compressor crankshaft and drive disc on cam­
shaft gear for worn or broken teeth.
2. Make sure mating surfaces of air com­
pressor or flange and flywheel housing assembly
are clean. Place new compressor to adapter gas­
ket on studs.
3. Insert drive coupling into hub on crank­
shaft. Place compressor in position on flywheel
housing assembly, guiding teeth on coupling into
mesh with teeth in drive disc. Install bolts and
tighten,
4. Connect all water, air, and oil lines, mak­
ing sure connections are tight.
5. Make sure drain plug is installed in com­
pressor cylinder block, then fill cooling system.
6. Adjust air compressor governor as di­
rected later.
UNLOADER ASSEMBLY
REPLACEMENT
Unloader assemblies on both Bendix-Westing -
house and Midland-Ross compressors can be
replaced without removing compressor from
vehicle. Since the unloader assemblies differ by
manufacturer, a separate procedure is given for
each.
BE ND IX - W EST IN G H O U SE
Parts are available in a kit for replacing un­
loader assembly. Unloader parts (fig. 5) may
be changed without removing cylinder head as
follows:
Plunger
Assembly
Spring
Spring Saddle
Plunger
j t t
WJ
Piston
Figure 5— Unloader Assembly Components IB-W)
Removal (Fig. 6)
1. Remove air inlet elbow and discard gasket.
2. Insert screwdriver blade under unloader
spring and raise spring off unloader spring
saddle. Remove spring and spring saddle.
3. Lift each plunger guide and remove guide
and plunger. Lift pistons out of bores. If piston
is not easily removed, build up air pressure in
system until governor cuts out, raising piston. If
compressor has been removed from vehicle, use
air pressure as shown in figure 6.
Installation (Fig. 7)
1. Carefully insert each piston, complete with
O-ring and back-up ring, in bore.
2. Slide plunger guide down over unloader
Figure 6 — Removing Unloader Components IB-W )
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH O P M A N U A L