TM 9-2320-289-34
Table 2-1. Mechanical Troubleshooting (Con’t)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 7.
Feel evaporator outlet line for warmth. If evaporator outlet line is warm, check for
frost spots on line. Frost spots on line indicate restrictions.
If evaporator outlet line is restricted, clear restrictions.
If evaporator outlet line is not restricted, perform step 8.
Step 8.
Check expansion valve temperature sensing bulb positioning. It should be wrapped
securely to evaporator outlet line with thermal insulation tape. (Item 67,
Appendix B) Thermal insulation tape should completely cover temperature sensing
bulb.
Adjust positioning if not correct.
If positioning is correct, perform step 9.
Compressed air
(207 kPa). Use
WARNING
used to test expansion valve should never exceed 30 psi
only effective chip guarding and Personnel protective
equipment (goggles/shield, gloves. etc.). Failure to follow this warning
may result in serious injury to personnel.
Step 9.
Remove expansion valve. (See paragraph 10-27) Check expansion valve for
clogged inlet screen.
Clear inlet screen if clogged.
If inlet screen is not clogged, attempt to blow through expansion valve using
compressed air not to exceed 30 psi (207 kPa). If unable to blow through
expansion valve, replace expansion valve.
2.
LOW OR NO AIR FLOW
Step 1.
Remove condenser cover assembly,
buildup on evaporator coils. If there is
(See paragraph 10-20)
If low pressure gage
step 2.
If low pressure gage
receiver-dehydrator.
(See TM 9-2320-289-20) Check for ice
ice buildup, test air conditioning system.
indicates that low side is below specifications, perform
indicates that low side is within specifications, replace
(See paragraph 10-27)
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