Any thoughts on chasing down ac leaks. I haven't had very good luck with dye. Are the cheap sniffers any good. I was thinking about a kit with plugs and adaptors that can isolate components and pressurize them kind of expensive though. I changed the evaporator about 10 years ago I hope that's not the problem again. 

Another spot that is common for leaks but shows no signs of leak is the compressor shaft seal will leak but the pullet will sling off any oil or dye so its tough to diagnose that one too.

 

Bad o-rings or too small of o-rings can leak too and sometimes not show dye either. If you do change o-ring make sure to have a bottle of PAG oil and lube the o-ring before snapping connections back together again. I've seen replacement parts like condensers and evaporators with the wrong sized o-rings too. 

 

Do you have enough oil in the system? Lack of oil sometimes can dry o-rings out a bit and allow them to leak the freon out without much dye because of lack of oil to push the dye around. 

 

 

My first leak was the evaporator. The next leak was the compressor. The first was impossible to see the dye and never could detect on the second. A new compressor fixed it. The clutch was going also so the decision was made easier.

Thanks for the help. I'll  keep checking. The compressor  is the original one.

GW,

 

If you have a nitrogen bottle, pressurize the system with nitrogen, and use bubbles.   The High side pressure switch does not open until 450psi.  So if you pressurize in the upper 300 to low 400 you can find small leaks with good bubbles.

 

This will get you everything you can see.  if you are still leaking, it has to be the evaporator.  Since you will have pressure and not having to run the truck, you may hear the leak. 

 

GL!

 

Hag

I've used compressed air one time and just vacuum it back off.

 

Another weird one I had to forceifully over charge a system to get the compressor to show its leak around the body seals once it was over charge and more liquid in the system it start to slowly push out after it sat for the night. 

I'll have to admit I used half a can of stop leak, been working fine for past two years now. Some day I'll probably just change everything in system and start over. 

I did mine about 3 years ago. Compressor, lines, drier for about $250 from RA, 3 months later the wifes 98 Saturn went. The compressor died. Cost me twice the money as the Dodge for the same parts.