TM 9-4110-258-13
5.39 COMPRESSOR B1 SERVICE, TESTING. REPAIR. AND REPLACEMENT. - Continued
(4) Replace dehydrator (para 5.15).
(5) Leak check (para 5.11), evacuate (para 5.12), and charge (para 5.13) the refrigeration system.
b. Testing.
(1) Remove two screws (3) and cover (4).
(2) Using multimeter set to measure continuity, check compressor (5) winding continuity between terminals 1
to 2, 1 to 3, and 3 to 2. Continuity should be indicated. If continuity was not indicated, replace
compressor.
(3) Using multimeter set to measure continuity, check compressor (5) winding continuity between each
terminal 1, 2, and 3 to compressor frame ground. No continuity should be indicated. If continuity was
indicated, replace compressor.
(4) Discharge refrigeration system (para 5.8).
(5) Remove eight screws (6), cylinder head (7), cylinder head gasket (8), valve plate assembly (9), two reed
valves (10), and valve plate gasket (11). Discard gaskets.
(6) Examine reed valves (10) for warpage and any other physical damage. Replace valve plate assembly (9)
if reed valves are damaged.
(7) Examine compressor (5) cylinder walls for any scoring or excessive wear (groove at top of piston (12)
travel. Replace compressor if scored or excessively worn.
(8) Press on top of highest piston (12). When pushed down, the higher piston should have some resistance
and the lower piston should rise. Repeat for other piston. If either piston was loose and did not cause the
other one to rise, replace piston and any other damaged components.
(9) If no failure was indicated, remove any gasket material from all machined gasket surfaces and install new
valve plate gasket (11), two reed valves (10), valve plate assembly (9), new cylinder head gasket (8),
cylinder head (7), and eight screws (6).
(10) Install cover (4) and two screws (3).
(11) Replace dehydrator (para 5.15).
(12) Leak check (para 5.11), evacuate (para 5.12), and charge (para 5.13) the refrigeration system.
c. Removal.
NOTE
Remove only items necessary to access defective component(s).
(1) Remove two screws (3) and cover (4).
(2) Tag wire leads (13). Remove four screws (14) and pull wire leads out through strain relief cable bushing
(15).
(3) Remove conduit locknut (16) and strain relief cable bushing (15).
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