Replacing The Compressor; Removing V-Belt From Engine Adapter Drive Sheave; Compressor Drive Assembly; Compressor - Carrier DM-4 Power Pack Operation And Service Manual

8. Turn off and check belt tension.
Figure A
Figure B
Figure 4-5. Removing V-Belt from Engine Adapter
Drive Sheave
Table 4-1. V-Belt Tension
Belt
Water Pump
Alternator

4.5 REPLACING THE COMPRESSOR

If compressor is inoperative and unit still has refriger-
ant pressure, frontseat suction and discharge service
valves to trap most of the refrigerant in the unit.
If compressor runs, pump down the unit.
1. Remove the two rear compressor mounting bracket
bolts (compressor shock mounts).
2. Block up engine.
3. Slowly release compressor pressure into a recovery
system.
4. Remove bolts from suction and discharge service
flanges.
5. Remove oil filter and bracket.
Tension
35 --- 40 foot pounds
70 --- 80 foot pounds
6. Disconnect battery ground cable. Unbolt power
relay and move out of the way.
7. Disconnect wiring to unloader valve assembly and
high and low pressure cutouts.
8. Remove ten bolts from engine compressor spacer.
9. Disconnect ground strap from frame.
10. Attach sling or other device to compressor.
11. Slide compressor enough to clear nylon drive gear,
Figure 4-4 and remove compressor from unit.
12. Drain oil from defective compressor before shipping.
13. The original unloader valve must be transferred to
the replacement compressor. The plug arrangement re-
moved from the replacement is installed in the original
compressor as a seal. If piston is stuck, it may be extracted
by threading a socket head cap screw into top of piston. A
small Teflon seat ring at bottom of piston must be re-
moved.
The service replacement compressor is sold
without shutoff valves (but with valve pads).
Customer should retain the original unloader
valve for use on the replacement compressor.
Check oil level
compressor. (Refer to section 1.7)
3
2

1. Compressor

2. Bolts
3. Spacer
4. Key
5. Compressor Drive Gear
6. Locking Tab
7. Nylon Drive Gear
8. Drive Sheave Bolts
9. Engine adapter-Drive Sheave
10. Alternator Belt
Figure 4-6. Compressor Drive Assembly
14. Remove the high and low pressure switches and
install on new compressor after checking switch settings.
Install compressor frame to new compressor (if removed
with defective compressor).
4-5
NOTES
in service replacement
9
7
6
4
5
1
8
10