Operation CHARM: Car repair manuals for everyone.

Fluid Leak Detectors


Testing the refrigerant system for leaks is one of the most important phases of troubleshooting. One or more of the methods outlined will prove useful in detecting leaks or checking connections if service work is performed. Before beginning any leak test, attach a manifold gauge set and note pressure. If little or no pressure is indicated, a partial charge must be installed. Check all connections, compressor head gasket, oil filler plug and compressor shaft seal for leaks.

Apply leak detector solution around joints to be tested. A cluster of bubbles will form immediately if there is a leak. A white foam that forms after a short while will indicate an extremely small leak. In some confined areas such as sections of the evaporator and condenser, electronic leak detectors will be more useful.