LEAK TEST -699581183

TM 9-2320-363-20-2

LEAK TEST

WARNING

Use care to prevent refrigerant from touching your skin or eyes, because liquid

refrigerant, when exposed to air, quickly evaporates and will freeze skin or eye

tissue Serious injury or blindness could result if you come in contact with

liquid refrigerant.

Refrigerant R-134a air conditioning systems should not be pressure tested or

leak tested with compressed air. Combustible mixtures of air and R-134a may

form, resulting in fire or explosion, which could cause personal injury.

NOTE

Refrigerant is odorless. As a result, all of it may leak away and not be noticed

until the system stops cooling. All vehicle refrigerant systems lose some

refrigerant, depending on the condition of the system. Higher loss rates signal

a need to locate and repair the leaks.

Leaks are most often found at the compressor hose connections and at the

various fittings and joints in the system. If unapproved replacement hoses are

Installed, refrigerant can be lost through hose permeation.

WHEN CHECKING FOR LEAKS, ALWAYS FOCUS YOUR ATTENTION ON THE LOWEST PORTION OF THE

FITTING OR PARTS BEING TESTED. REFRIGERANT IS HEAVIER THAN AIR AND WILL COLLECT AT LOW

POINTS. OIL WILL ALSO FLOW THROUGH LOW POINTS.

LISTED IN SEQUENCE FROM LEAST PRECISE TO MOST PRECISE, TH E METHODS FOR LOCATING LEAKS

ARE:

SOAPSUDS SOLUTION. A SOLUTION OF SOAP AND WATER CAN BE SQUIRTED ONTO A SUSPECTED

FITTING OR PART. IF THE LEAK IS LARGE ENOUGH, IT WILL CAUSE BUBBLES TO FORM IN THE SOAPY

SOLUTION AT THE POINT OF THE LEAK.

NOTE

DO NOT use leak detector immediately after connecting or disconnecting

refrigerant hoses. Traces of refrigerant at fittings can falsely signal a leak.

ELECTRONIC LEAK DETECTOR. A FAIRLY RECENT DEVELOPMENT, ELECTRONIC LEAK

DETECTORS ARE BATTERY OR 115-VOLT POWERED AND RELY ON A VERY SENSITIVE

SIGNAL WHEN A LEAK IS FOUND. IN ADDITION TO BEING VERY PRECISE, ELECTRONIC

LEAK DETECTORS CAN BE USED IN TIGHT PLACES.

FOLLOW LEAK DETECTOR

MANUFACTURER'S INSTRUCTIONS TO TEST FOR LEAKS.

NOTE

Follow-on Maintenance:

Check operation of heater/air conditioner (TM 9-2320-363-10).

Change 3 4-879/(4-880 Blank)