Is my AC Evaporator Leaking?

I have a 2008 4x4 quad cab 4.0 with 120K miles. In the last 5 years I've only put about 3K miles on it. Two summers ago I noticed it wasn't cooling well and took it to my local friend/mechanic. A pressure test revealed no refrigerant and a visual inspection revealed no leaks so he charged it up and put a dye. The next summer I had the same no cooling issue so I took back to him. Again, no refrigerant and no obvious leaks of the dye. He charged it again and said it may be the evaporator (under dash). He asked if I smelled anything in interior when first starting up truck and I do not. This charge only lasted a couple months before not cooling effectively.

According to him, the evaporator is likely leaking but a big job. Since he only charges me $40 for recharging he suggested I could do that routine for some time considering what a PITA the job is.

I've seen YouTube videos of evaporator replacement and the entire dash has to come out - terrible. I'd hate to go through all that and not fix the issue. Has anyone here run into a similar issue successfully repaired by swapping evaporator? Any other advice I'm overlooking before I dive in?

 

I have seen compressor seals leak with no evidence as well. If the system has dye in it and the evaporator is indeed leaking usually dye will come out of the AC drain with the condensation. The service ports would be another area to check for leaks.

 

A borescope in the evap case might be helpful for a look around. Ones that attach to your cell phone aren't too expensive.

A good AC shop should have a sniffer too. Put that in the case and see what happens.

 

You can buy a sniffer on Amazon for about 50 bucks. If you have black light ( flash light type amazon 20 bucks) go out side after dark and shine the light everywhere the lines go. You will see the dye. Use sniffer to verify. Replace what is bad and repeat untill no more leaks.

 

good tips - keep 'em coming.

 

I would recharge with some added dye, give it a few days and look at night with a UV light. Also look on the edges of the condenser. Front and back. Rule out the easy stuff first.

 

Charge it up and drive the truck more, with the AC on so the dye is circulating. Drive it a lot with the AC always on. The dye will show up. Look closely at the high side hose and connections, and the end of the evap drain tube.

 

Having the same issue. My problems seem to have started after our weird freeze last winter here in Texas. I have added the dye twice (just in case) and have not been able to locate the leak with a decent UV light and several attempts.
I had kind of given up, but I am stubborn and a glutton for punishment.
That is interesting about the compressor leaking and not pushing any dye out.
My charge will disappear in less than a day, so I would think the leak is pretty big.

My mechanic friend seemed to think that the evaporator is most likely fine and that the likely leak spot is a seal at the connection to the evaporator.
Will probably get a sniffer as suggested before pulling the dash (ugh!).
Have not seen any dye at the condensate drain opening yet, so I am a bit baffled.

I also had a pretty significant leak at my low side charging port, but that seems to hold pressure now.

If I was to pull the dash, what components would you guys recommend I have on hand to replace?

 

OP.....suggest you find a mechanic with better diagnostic skills, preferably an AC specialist.

Your current mechanic thinks it might be........ Or in other words, just fire the parts cannon until the problem is fixed......or bandaid it each year with a $40 freon charge.

 

Thanks for the advice, but I am actually trying to repair it myself because I am poor.

 

Turn the ac on full blast and try to get it to drip some condensation out the drain tube. If anything in the hvac box is leaking the dye should come out the drain tube with the water. It'll look like green alien blood

Also check the service valve cores closely

 

A sniffer should find that leak quickly.

 

Take it to an AC mechanic, pay a small fee for diagnosis and a repair quote. Get the quote in writing with details........