AIR CONDITIONING SYSTEM GENERAL MAINTENANCE AND TESTING

TM 9-2320-312-24-1

AIR CONDITIONING SYSTEM GENERAL MAINTENANCE AND TESTING

PRELIMINARY CHECKS

Before testing operation of air conditioning system, make the following checks:

Ensure AC compressor drive belt is not damaged and is under proper tension. Check compressor mountings for tight-

ness.

Check for broken, burst, and cut hoses. Check for loose fittings on all parts.

Check for road debris buildup on condenser coil fins. Using air pressure and a whiskbroom or a soapy spray of water,

carefully clean condenser, using care not to bend fins.

Check color in moisture indicator sight glass. If color is a deep cobalt blue, refrigerant charge is dry. If moisture indica-

tor is not blue, system is contaminated with moisture. Notify your supervisor.

If there is not enough airflow, ensure that leaves and other debris has not entered fresh air ports under windshield. If

debris is present, it could clog fins of evaporator core and block airflow. Ensure that all ducts are connected to dash lou-

vers and air-control flaps in heater housing are moving properly.

SAFETY PRECAUTIONS

Whenever repairs are made to any air conditioner parts that hold refrigerant, it is necessary to discharge, purge or flush

(if contaminated), evacuate, charge, and leak test system. In a good system, refrigerant lines are always under pressure

and should be disconnected only after air conditioning system has been discharged to a refrigerant recovery unit through

service valves on compressor.

Refrigerants are safe when used under proper conditions. Always wear safety goggles and non-leather gloves while dis-

charging, purging, flushing, evacuating, charging, and leak testing system. DO NOT wear leather gloves. When refriger-

ant gas or liquid contacts leather, leather will stick to skin.

WARNING

Liquid refrigerant, when exposed to the air, quickly evaporates and will freeze skin or eye tissue. Use care to

prevent refrigerant from touching your skin or eyes. Serious injury or blindness result if you come in contact

with liquid refrigerant.

Refrigerant splashed in eyes should first be treated with a few drops of sterile mineral oil in eyes, and rinsed with a weak

boric acid solution. DO NOT rub eyes. Seek medical attention immediately.

Refrigerant splashed on skin should be treated the same as frostbite. Gently pour cool water on area, but do not rub skin.

Keep skin warm with layers of soft, sterile cloth. Seek medical attention immediately.

Even though refrigerant does not burn, when it contacts extreme heat or flame, poisonous phosgene gas is created. This

gas is also produced when an open flame leak detector is used. Phosgene fumes have an acrid (bitter) smell.

WARNING

DO NOT work in an area where refrigerant may contact an open flame or any burning material such as a cig-

arette. When refrigerant contacts extreme heat, refrigerant breaks down into poisonous phosgene gas which,

if breathed, causes severe respiratory irritation. DO NOT breathe fumes from an open flame leak detector.

You must work in an area where there is a constant flow of fresh air when system is discharged, flushed, charged, and

leak tested using an open flame leak detector.