Visual Inspection

BEFORE PERFORMING ANY PERFORMANCE TESTS, BEGIN WITH A VISUAL INSPECTION FOR:
- Obstructed air passages.
- Broken belts.
- Disconnected or broken wires.
- Loose clutch.
- Loose or broken mounting brackets
- Many refrigerant leaks.

REFRIGERANT LEAKS
A refrigerant leak will usually appear as an oily residue at the leakage point in the system. The oily residue soon picks up dust or dirt particles from the surrounding air and appears greasy. Through time, this will build up and appear to be a heavy dirt- impregnated grease.

O-RING LEAKS
Most common leaks are caused by damaged or missing 0-ring seals at the various hose and component connections. When these 0-rings are replaced, the new 0-rings should be lubricated with refrigerant oil. Care should be taken to keep lint from shop towels or rags from contaminating the internal surfaces of the connection. Leakage may occur at a spring lock coupling if the wrong 0-rings are used at the coupling.

SCHRADER VALVE LEAKS
Another type of leak may appear at the internal Schrader-type A/C charging valve core in the service gauge port valve fittings. If tightening the valve core does not stop the leak, it should be replaced.

SERVICE PORT VALVE CAPS
Missing service gauge port valve caps can also cause a refrigerant leak. If the valve cap is missing, dirt will enter the area of the A/C charging valve core. When the service hose is attached, the valve depressor in the end of the service hose forces the dirt into the valve seat area. The dirt will destroy the sealing surface of the A/C charging valve core. When a service gauge port valve cap is missing, the protected area of the A/C charging valve core should be cleaned. A new service gauge port valve cap should be installed.

CAUTION: Service gauge port valve caps must be installed finger tight. if tightened with pliers, the sealing surtace of the service gauge port valve may be damaged.