Since about 09 my A/C in my 91 bird has blown hot air. It has been retrofitted with r134a and when I have tried to refill it, it would last about a week or two and leak a bitter smell into the cabin and make me sick. The freon would leak out into the cabin until it would eventually just blow hot air again. Can anyone give me an idea as to what might be causing this and what might need to be replaced? Thanks!

 

You already identified the cause (there's a leak).

You need to ID where the leak is and repair it. A visual inspection might tell you where the leak is, evidenced by the presence of refrigerant oil. Otherwise, you'll need to get a leak detector, partially fill the system with refrigerant and start sniffing with the detector.

No guessing here. There are numerous places leaks can occur. If you don't have leak detector you'll need to take it to a shop.

 

you can get die and install it in the ac system then get a die light and check that away as well, if you know for a fact its leaking inside the cabin, it could very well be your evaporator core!, you should do as paulo57509 said, but remember the die works just as good

 

retrofitting an ac for 134a is more than just putting in 134a and a couple of fittings.

your acumulator definately needs replacing being exposed to air that long. you might have leaks else where.

you will need a manifold set a vacuum pump 1 can of 134a and dye to properly diagnose. all of this can be gotten from auto stores.

its not as hard a job as it seems.

once you find the leak replace those parts dont use that leak stop crap. you will need to add refrigerent oil compatable with 134a for each major component you replace if they dont come pre-oiled ammounts vary.

great link for ac info dealing with 134a and thirdgens https://www.thirdgen.org/retrofitac

 

If it is getting into the cabin then as 90camaro355rs said more then likely the evaporator is bad.

 

Sorry for the late response guys, do you think I would just be better off taking it to a shop? Taking out the evaporator core is quite a job.

 

Taking out the evaporator core is relatively easy on a third gen. It is right behind that silver canister behind the passenger side shock tower. The silver canister is your receiver drier. It connects to the evaporator. The black box that houses the evaporator comes apart. Once the cover is off, you can slip the evaporator out, either with the receiver drier connected or not. I would put in a new receiver drier also, since they absorb moisture once the system is opened. Also, change out all the seals on the system before buttoning it back up.

 

You're saying I don't have to tear into the dash to get to it? I had no idea.

 

Yep - no need to take apart the dash. You have to dig into the dash for a heater core.

 

Thank you recaro!

 

I just looked around in the engine compartment and it seems like the leak is coming from the a/c compressor. There's a fair amount of black gunk around the back of it so given that the compressor hasn't been changed in the ten years I've had it I'll swap it out and see if that fixes the problem.