Jeep A/C leak can't be found

[HawkeyeScott]

Ever had one of those problems you just can't seem to fix? Man, I am getting frustrated by this one.

2001 Jeep Cherokee 4.0 had a leak in the A/C system. Dye was used and the leak quickly located. Mechanic changed the accumulator and the hoses that lead into and out of it.

But since getting it back, all the coolant has leaked out of the system. Twice. Mechanic cannot find the new leak, even after using the dye again. Said he tried last week to pinpoint it spraying water to areas he couldn't see and looking for the dye-stained water. Still didn't work.

And here's the tricky part. The Jeep blows cold air, cold air, cold air, and then all of a sudden the coolant is gone. A week after he recharged it this last time, it was blowing 46-degree air a week later. Four days after that, it's not blowing any cold air at all and there's still no dye to be found.

Any help would sure be appreciated.

-Scott

 

[johnd]

The one place you cannot see is inside the evaporator coil box. Have him look in there. This happened to me once.

 

[punisher]

What type of leak detector is being used besides dye?

Assuming the evap core checks out, I have found that a faulty compressor front seal can be a bear to track down. Many times a front seal will only leak when the compressor is actually turning and the refrigerant is under pressure. Leaks can also occur without much oil (hence UV dye) being present on the clutch.

As a tech I hated that sort of head scratcher.

 

[daman]

Did he try a electronic leak detector?? (sniffer)

allot of times you can't find a leak with dye because
it's too small, often i've found leaks with my sniffer
that dye couldn't..

 

[HawkeyeScott]

Thanks for the help so far. I think he has only used the dye-glasses-blacklight method.

Could having changed the other stuff somehow created a new leak in the evap. coil box?

Head scratcher is right. But we're not giving up.

 

[kc8adu]

just had one in that acted like that.evap had a mouse nest on top.urine severely corroded it.

 

[GMBoy]

I had the same issue with my 2000 Cherokee. The evap in the dash was leaking. Fill it and than use an AC sniffer in the dash vents. This is not too bad of a job, but certainly not the most enjoyable. While you're there - do yourself a favor and change the heater core too - it sits right there too and you DO NOT want to do this job again. You have to pull the dash away from the fire wall to get to it. I did the job myself in about 4 hours. Be sure to have the factory Jeep manual, it helps. This leak seems to be a common Jeep AC failure mode - I've seen 2 other Jeeps with AC leaks here too. Just my input from my experiences. Good Luck.