TM 5-4310-344-34
2-45.
CLEANING AND INSPECTION.
f.
Position first stage cylinder head and valve
assembly and gasket (16) on first stage cylinder so that
cooling fins all slanted down toward fan end of
a. Clean all parts with dry cleaning solvent,
compressor. Install flat head screws (5) and tighten with
Federal Specification P-D-680.
a torque of 25 pound-inches.
b. Inspect all parts for obvious indications of
g. Install air intake filter (3) and cover (1) with
damage such as damaged screw threads, scratched,
screws (2).
pitted, or worn finished surfaces, and broken cooling
fins.
h. Connect the intercooler assembly to the
cylinder port.
c. Inspect the cylinder bore, piston, piston
rings, piston pin, master rod, and bearings for excessive
2-47.
SECOND STAGE CYLINDER, PISTON, AND
wear, scoring, and other damage.
VALVE.
d.
Refer to table 2-1 for wear tolerances.
2-48.
2-46.
a. Disconnect the intercooler assemblies at
a. Attach first stage piston assembly (18) to
the second stage inlet and outlet ports (paragraph 2-40).
master rod and needle bearings with piston pin (20) and
retaining rings (19).
b. Unscrew and remove strainer and relief
valve assembly (9). Remove flared nut (10), back-up
b. Install shim (22) between two paper
ring (11), and gasket (12).
gaskets (21), against mounting flange of first stage
cylinder (17).
c. Remove elbow (13), flared nut (10), back-
up ring (11), and gasket (12).
c. Compress the piston rings and slip first
stage cylinder (17) over installed piston and press into
d. Unscrew cylinder cap (4) and remove
crankcase mounting hole. Cylinder must be installed
exhaust valve (8), valve spring (7), valve spring washer
with leading edge of cooling fins slanted toward fan end
(6), and preformed packing (5).
of compressor. Secure cylinder to crankcase with nuts
(23), being sure to tighten with an equal torque.
e. If the rupture disc (3) is defective, unscrew
disc holddown screw (1) and remove disc retainer ring
d. Use a depth micrometer or dial indicator to
(2) and rupture disc (3), from the cylinder cap (4).
measure
piston-head-to-valve-plate
clearance.
Required clearance is 0.021-to 0.026-inch. If necessary,
f.
Remove nuts (15) and carefully slide
remove cylinder and add or remove cylinder-to-
cylinder (14) over the piston assembly (18).
crankcase gaskets to obtain required clearance.
g.
Remove and discard gaskets (16) and (17).
Note
h. Remove cotter pin (20) and carefully push
Overall thickness of steel gaskets can
piston pin (19) out of the piston assembly (18). Use
be reduced in increments of 0.002 inch
care to prevent loss of the 25 needle bearings (22) and
by peeling off laminations. At least one
two washers (21) which will drop out of the piston
paper gasket must remain on each side
assembly when the piston pin is removed. Scribe a
of steel gasket in final installation.
small mark on the inside of the piston skirt toward the
fan end of the crankcase for correct reassembly.
e. Install packing (9) in groove in first stage
cylinder head (4). Assemble valve stop (10), exhaust
i.
Do not disassemble the piston assembly.
spring (11), exhaust valves (12), valve plate (13), intake
valve (14), and intake valve spring (15).
Attach
assembled parts to cylinder head with bolt (8), flat
washer (7) and nut (6).
2-10
