MCi Crusader II 1989 Maintenance Manual page 142

Date
1-1-89
Page __
4_-1_2 _ _
MC-9 MAINTENANCE MANUAL
inlet passage opens. Reservoir air pressure then flows past the
open inlet valve. through the passage in the piston and out the
unloader port to the compressor unloading mechanism, The
air, besides flowing to the compressor unloading mechanism,
also flows around the piston and acts on the additional area of
the piston, assures a positive action and fully opens the inlet
valve.
As the system reservoir air pressure drops to the cut-in
setting of the governor, the force exerted by the air pressure on
the piston will be reduced so that the pressure setting spring
will move the piston down. The inlet valve will close and the
exhaust will open. With the exhaust open, the air in the unloader
line will escape back through the piston through the exhaust
stem and out the exhaust port
MAINTENANCE
After 15.000 miles (24,000 km). clean or replace governor
filters. If cleaning, use a solvent which is known to have no
detrimental effect on metal or rubber material. If filters are
removed they should be replaced with new filters.
After 100.000 miles (161,000 km). disassemble the governor
and clean and inspect all parts. Refer to figure 4-13.
SERVICE CHECKS
1. Start the engine and build up pressure in the air system
and check the pressure registered by the dash gauge or test
gauge at the time the governor cuts out. stopping the compres-
sion of air. The cut-out pressure should be approximately
115-118 psi (793-814 kPa) maximum.
2. With the engine still running, make a series of brake appli-
cations to reduce the air pressure and observe at what pressure
the governor cuts in the compressor. Cut-in pressure should be
95-105 psi (655-724 kPa).
NOTE: Neyer doubt or adjust the goYemor
pressure settings unless they are checked
with an accurate lest gauge or a dash
guage that is registering accurately.
3. If the pressure settings of the governor are inaccurate or it
is necessary thatthey be changed, unscrew the cover at the top
of the governor and loosen the adjusting screw locknut
4. With a screwdriver. the adjusting screw is turned coun-
terclockwise to raise the pressure settings. and turned clock-
wise to lower the pressure setting.
5. After the adjustment is completed. the adjusting screw
locknut should be tightened to lock the setting.
21
5
1.
Valve Spring
10.
Spring Guide
16.
Exhaust Stem
2.
Valve
11.
Upper Spring Seat
17.
Exhaust Stem Spring
4.
Piston
12.
Nut
18.
Body
5.
0-ring 13. Adjusting Screw
20.
Filter
6.
Washer
1-4.
Cover
21.
0-ring
8.
Lower Spring Seat
15.
Retaining Ring
22.
Pipe Plug
9.
Spring
Figure 4-13. Governor Parts Breakdown.