I cannot find the leak in my AC and suspect it is in the evaporator, which is inside the dash. Before I go through the trouble to tear it out I want to try testing it with a pressure test fixture that I would build. Would anyone have an old AC line they would part with, or just the fitting end at the firewall? I may be going in the wrong direction with this, so I am open to suggestions. Thanks!

 

FWIW, folks have reported leaks at the ports themselves at least a couple of times in recent memory...

 

an easy way is to go to your local auto parts store and pick up a a/c top up kit,you can buy just a can or a kit that includes a flexible hose. Make an adapter to your home tire compressor and listen for a leak if its large enough or use a soapy water in a spray bottle

 

Often the a/c system is charged with a dye that can be seen with a black light or you can use a refrigerant sniffer. I found the sniffer to be a good tool.

Link Electronic Freon and Halogen Leak Detector

When checking with the sniffer you system must be under pressure and the engine off for best results.

 

My son is a little bit more up on AC than I am. Why do you think you have a leak. There are many other things that can make an A C not work. Did you hook the system up to a set of gagues. My son and I introduce a dye in the system to spot leaks. I just got my A C in my F350 fixed today. Recharged the system with die and found no leaks. Thought it was a high pressure switch and that didn't fix it. Today figured out it was the A C clutch and now I have A C again . Just in time because today it going to be 104.

 

I went the dye route and can't find any evidence of it, not even at the seals. The ac works when charged, then the pressure bleeds off (I have a gauge set). The pump works correctly when there is a full charge, then does the on/off cycle thing until there isn't enough gas. So back to the original question...

 

It looks like I wasn't clear what I want to do, which is to make a pressure test fixture for the evaporator only by blocking one side and applying pressure to the other, with a gauge tee'd off to check for bleed down.

 

Take a picture of what you need. I have 2 parts cars. PM me with your address and I'll send it to you.

 

Depending on how long it takes for your AC to lose pressure, there are products out there that you can just add to the system.

I have a product in my system called AC Pro Super Seal, and it repairs metal leaks and seals rubber leaks. It cost me a little over $35 at Menards, and has lasted for a couple of years now. I have even used it to repair the condenser on a Ferrari. You just need to follow the instructions, or it will seal off the charge port.

Chances are the aluminium pipes are seized together, and you will end up opening up a hornets nest trying to replace the evaporator, like you were talking about.......Good Luck........Mike

 

First off do not use a stop leak you could regret it later!

If it were me I would add the leak dye without sealer and pressurize the system with one can of Freon and see if you can find the leak that way. If it is not under the hood then look inside.

I had replaced my compressor and dryer and did a complete flush on the system and pulled a vacuum for about an hour and no leaks charged the system and had a leak. The leak was at the dryer one of the “O” rings I replaced. Changed it and all was good.