Reply to "How do you remove the Evaporator?"

Emery, BD,

R134a is not compatible with the mineral oil lubricant or the viton / buna-N elastomers (o-rings, seals, compressor parts, hoses) that were used in your R12 a/c system. And the heat absorbtion properties of R134a are different from those of R12. So a properly done conversion will flush all the mineral oil from the entire system, replace the receiver-dryer, expansion valve, compressor, any rubber hoses and all the o-rings and refill with the correct poly alkaline glycol lubricant. Replacement R134a specific service fittings are screwed on at the service ports & a big R134a decal is attached near the service ports as well.

The R134a has probably chewed away at an old o-ring or a thin spot in an old hose.

I search for leaks by purging the system & pressurizing it with air (Ron uses N2 which is better because it is dryer). No need to blank off anything, just apply pressurized air to one of the service ports & pressurize the entire system to about 100 psi. Then I apply a liquid specifically designed to locate gas leaks in tubing systems (Snoop, sold by the Swagelock Company) at all the fittings, connections, etc. It creates bubbles where the leak is located.

Often Snoop applied to a fully charged, non operating system will be enough to find the leak. Fully charged, a non operating R12 system develops about a 70 psi pressure throughout the closed loop system. I'm not sure about R134a.

An a/c shop will have an electronic monitor that detects halogen gases, a detector like that is often successful at closing in on the location of a leak. I would think it would be money well spent to let an a/c shop locate the leak, rather than tearing apart your car needlessly.

your friend on the DTBB