Leak Test - Service Ports/Access Valves

A/C Hose Routing And Service Port Locations:

The primary seal for the service port is the sealing cap. This cap contains a specially designed O-ring or gasket which provides a leak-free seal. Should the cap be loose, missing, or the wrong cap used, it could result in a loss of refrigerant charge. The HIGH side port is identified with a BLACK cap and the LOW side with a BLUE cap.