TM 5-4310-384-13
b.
Remove cylinder (2) by twisting slightly back and forth while pulling upward.
c.
Discard old cylinder gasket (4).
CAUTION
Pistons, connecting rods, piston pins and caps are matched parts and seat with the operation of the
compressor. They must keep their original positions at reassembly. Mark each component to be sure they
match when they are reassembled. Also mark the cylinders from which they are removed.
d.
Turn crankshaft (5) until low pressure piston (6) is at top dead center (TDC).
e.
Remove capscrews (7 and 8) securing cap (9) to connecting rod (10). Capscrew (8) is an oil slinger.
f.
Remove entire piston assembly and reattach parts (7, 8, 9 and 10) in original position and mark for reassembly.
g.
Turn crankshaft (5) until high pressure piston (11 ) is at TDC and repeat above steps e and f.
h.
Remove capscrews (12) securing breather chamber cover (13). Remove cover.
i.
Discard cover gasket (14).
j.
Remove felt oil separator (15) and breather element (16).
k.
Remove crankcase cover (17).
I.
Remove and discard crankcase cover gaskets (18) used as shims.
m. Remove crankshaft (5) with bearings (1 9) and cups (20) in place. Leave bearings on crankshaft until after
inspection.
n.
Remove oil drain cap (21), and pipe nipple (22).
o.
Remove fill plug (23).
p.
Remove oil seal (24) by driving out from inside of crankcase and discard.
q.
Do not remove oil level gage (25) unless broken or unreadable. Gage is press fit into crankcase and removal by
driving out will damage it.
INSPECTION.
a.
Inspect cylinder (2) for cracks, broken cooling fins, and scored cylinder. Replace as necessary.
b.
Inspect pistons (6 and 11) for cracks, broken ring seats, or scored surfaces. Replace as necessary.
NOTE
Piston rings should not be reused as they will not seat themselves in the cylinder bore in the same position
as they originally were in.
c.
Inspect piston rings for any signs of wear. New piston rings should normally be installed during cylinder
assembly.
d.
Inspect connecting rods (10) for scored bearing surfaces and loose fit. Replace as necessary.
CAUTION
Crankshaft bearings and bearing cups are matched sets. If bearing replacement is necessary, replace
both bearing and cup.
e.
Inspect crankshaft (5), bearings (19), and cups (20) for scored journals or pitted bearings. Replace as necessary.
Refer to paragraph 4-9.
4-5
