Once a week my pressure on the low side reads 20lbs. I cannot find a leak. There is no smell in the cabin and no oil that I can see on any hose or fitting. Anyone have suggestions? I'd like to find my leak.

 

Hi coastaljag98,

Do you mean that the rest of the week the low side pressure measures higher? Lots of variables can affect your pressure readings. Do your ambient temperatures vary widely? Are you always measuring at the same engine rpm (above idle) with the A/C on MAX? And with the electric cooling fans pulling air through the condenser?

What is prompting you to check the pressures - is the compressor cycling off and not restarting? When your low side pressure is 20psi, is your high side pressure also low?

Are you adding refrigerant when you get the low pressure readings?

The UV dyes are usually a reliable way to find leaks (unless the leak is in the evaporator inside the dash). They have fluorescent dyes too, now, but I haven't tried them.

Hopefully some of our more knowledgeable A/C gurus will chime in.

Cheers,

Don

 

The automotive A/C gurus all hang out over on the following forum. You will definitely need to provide more detailed info.
Automotive Air Conditioning Bulletin Board ? View forum - A/C Questions and Opinions

As Don noted, UV dye usually works really well. I did have a small leak at a compressor seal on another vehicle that I needed to use the electronic sniffer to find.

Just replaced the compressor on my XJR, UV dye clearly showed that problem.

 

It's leaking out somewhere. Compressor woukdnt engage when it was down to 20psi on the low side. I gassed it up to 40psi last week andit lasted a week. Same deal this week. Not sure how much to put in but can't see any oily residue on any hose or the compressor. I smell nothing inside so not thinking evaporator.

 

Try some UV dye - I bet you'll find the leak. Hopefully it's just an O-ring in a joint somewhere. Once you find and repair the leak, I highly recommend you visit a knowledgeable specialist to have the system evacuated of air and moisture and then recharged with the correct amount of oil and refrigerant.

Please keep us informed.

Cheers,

Don