GMC 4000 Series Service Manual page 397

Sec. 6T
Page 386
AIR COMPRESSORS A N D GOVERNORS
it. If governor cuts out before 115 psi, turn adjust­
ing plug (1) in one turn and repeat this step.
3. If governor does not cut-out at 115 psi,
slowly turn adjusting plug (1) out until governor
cuts out.
4. Slowly bleed down air pressure until gov­
ernor cuts in at 93-98 p si. (If it does not cut-in at
stated pressure, loosen exhaust valve housing lock
nut (5).
5. If cut-in pressure is below 93 psi, hold
adjusting plug (1) and turn exhaust valve housing
(7) out approximately 1/6 of a turn. Repeat step 4.
6. If cut-in pressure is above 98 psi, hold ad­
justing plug (1) and turn exhaust valve housing (7)
1 Rubber Cover
2 Cover Retaining Ring
3 Lock Nut
4 Upper Spring Seat
5 Adjuster Screw Spring
6 Lower Spring Seat
7 Spring Guide
8 Lower Spring Seat
9 Adjuster Screw
10 Piston Grommet
4
\
, \
\
G M C S E R V I C E M A N U A L
Figure 7 — A ir C om pressor G ov e rnor (M -R )
in approximately 1/6 of a turn. Repeat step 4.
change of 5 psi. The difference between cut-in and
cut-out pressure must not be le s s than 15 psi as
it could result in erratic operation.
en both lock nuts (5) making sure the adjusting plug
(1) and exhaust valve housing (7) settings are not
changed.
BENDIX-WESTINGHOUSE (Fig. 8)
the governor.
Figure 8 — A ir Compressor G overnor (B-W )
1 Adjuster Plug
2 Lock Nut
3 Spring
4 Spring Guide
5 Housing Lock Nut
6 Housing O-ring
NOTE: One-sixth of a turn will result in a
7. Recheck cut-out and cut-in p ressu res. Tight­
1. Unscrew rubber cover and remove it from
2. Loosen adjusting screw lock nut.
11 Exhaust Stem
12 Exhaust Stem Spring
13 Washer
14 Exhaust Stem Grommet
15 Piston
16 Valve
17 Valve Spring
18 Piston Grommet
19 Governor Body
7 Housing
8 Valve Assembly
9 Governor Body
10 Filter
11 End Cap
T - 1 8 2 2
- 9 3 9 8
t p m