TM 55-2210-224-34
4-8.
AIR COMPRESSOR ASSEMBLY (cont) ASSEMBLY (cont)
WARNING
Procedures specify the heating and cooling of parts to aid in assembly. The heated
or cooled parts may cause injury to personnel if hand protection is not worn when
handling. Wear protective gloves for maximum protection.
90.
Place pulley (4) on an induction heater and heat to 250°F (210°C).
91.
Install square key (5) on shaft of crankshaft (166). Remove pulley (4) from heater and install on shaft of
crankshaft over square key. Install nut (3) and tighten two setscrews (2). Torque setscrews to 16 +1 lb-ft (22.4
+1.4 N.m).
92.
Position unloader air line and connect fittings (1).
TEST
93.
Perform an orifice test by the following:
CAUTION
When performing orifice test, check that oil pressure is never less than 15 psi (105
kPa). Damage to air compressor can result.
a.
Connect an orifice holder with 17/64-inch (6.75 mm) orifice in air reservoir drain cock. Use orifice with
square edges bored through plate 1/16 inch (1.59 mm) thick.
b.
Refer to TM 55-2210-224-12 and start engine and run until it is at normal working temperature.
c.
Close outlet valve from reservoirs, open drain cock, and leave open for all tests.
d.
Operate air compressor at least 2 minutes at low speed (300 rpm) and take a pressure reading. Record air
compressor speed (rpm) and corresponding pressure.
e.
Operate air compressor at least 2 minutes at high speed (600 rpm) and take a pressure reading. Record air
compressor speed (rpm) and corresponding pressure.
f.
Operate air compressor 15 minutes (drain cock open) and repeat steps d and e.
4-30
