Initial Inspection and Diagnostic Overview

VISUAL INSPECTION
^ Obstructed air passages, broken belts, disconnected or broken wires, loose clutch, loose or broken mounting brackets and many refrigerant leaks may be determined by visual inspection of the parts.
^ 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.
^ 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 well lubricated with refrigerant oil and 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. Use only the 0-rings listed in the Ford Master Parts Catalog for the spring lock coupling.
^ Another type of leak may appear at the internal Schrader type A/C charging valve core in the service access gauge port valve fittings. If tightening the valve core does not stop the leak, it should be replaced with a new 19D701 or equivalent A/C charging valve core.
^ Missing service access gauge port valve caps (19D702) can also cause a refrigerant leak. If this important primary seal (the valve cap) is missing, dirt will enter the area of the A/C charging valve core. When the test equipment service hose is attached, the valve depressor in the end of the service hose forces the dirt into the valve seat area and the dirt will destroy the sealing surface of the A/C charging valve core. When a service access gauge port valve cap is missing, the protected area of the A/C charging valve core should be cleaned and a new 190702 service access gauge port valve cap should be installed.

CAUTION: Service access gauge port valve caps must be installed finger-tight. If tightened with pliers, the sealing surface of the service access gauge port valve may be damaged.