A/C - Tips on Finding Refrigerent Leaks

A/C Leak Checking

Here are some tips on finding the source of a slow (and, therefore, elusive) refrigerant leak:

^ Check fittings and components with your leak detector below the area you're checking. R-12 is heavier than air and tends to concentrate around the bottom of fittings and seals.

^ Test the evaporator by inserting your leak detector into the evaporator drain hose. Don't insert it into the vents the blowing air may fool some detectors into indicating a false leak.

^ Check the compressor shaft seal with the compressor both on and off. Some seals will leak only when the compressor shaft is spinning, while others will leak only when it's at rest. Disconnect the condenser fan to settle the air around the compressor.

^ If you still haven't found the leak, install your pressure gauges to monitor the system pressure. Block the air flow to the condenser and run the system. Blocking the condenser's cooling air will make the high side pressure go up (don't let it go over 300 psi, and keep an eye on the coolant temperature gauge). Recheck all the components on the high side. Still no leak? Turn the A/C off, wait for the system pressures to equalize, then check the low side components again.