2. LOW OR NO AIR FLOW

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) 2-11