Hey everyone. Looking for some advice.

Since I got the car, ac has been stone dead. Took it to a shop, they repaired a leak and retrofit the girl. Worked for about 2 days. I'm hunting a huge leak. The shop quoted me 1 grand for complete ac replacement. However I believe only two parts have failed.

For starters, the compressor now has a knock. So that will be replaced.

Now I have an idea of where the leak is, mind you it is a huge leak. Barely lasts a day. Barely noticeable during the day, but at night, with ac running/freon in system, there is a bad fog on the back side of the windshield. It makes night driving very difficult.

I cleaned it off, and with no ac in the system, it does not fog, and the heater core has recently been replace maybe 2 months ago.

My question is, is the fog on the windshield due to a freon leak? If so, what component? I assumed evaporator but that's in the engine bay.

Any help I'd really appreciate it. AC in Texas would be very nice. But I only paid 2k for the car, don't feel like spending half the value to have the ac work again .

 

If it fogged the windshield then yeah, it probably is the evaporator. Not a fun job to do while the engine is in the car. Once out, you can either have it repaired or replaced. Make sure the shop doing the work leaves a vacuum on for at least an hour before adding refrigerant. They probably will be hesitant since they're real busy.


Did you like the way R134 cooled? I had my '87 Monte SS converted and was disappointed, to say the least. I have kept my '89 IROC R-12. Its interesting how often I run into people trying to sell the R-12 they have!

 

What stumps me is the window is fogged up on the inside and the evaporator is outside. I'm not well educated on how ac systems work or even the components on these cars lol.

I honestly enjoy it. My dad had a 84 with r12 and that was a great system but I feel the 134a cools just as well. The FBI level tint that the previous owner put on may help with that too haha

 

r-134 run lower pressure try filling you retrofit car to 80 percent of recommened level see if that works

 

The evaporator and the heater core are next door neighbors. Lol! Once the refrigerant flows through and cools it, the fan forces air past the cold evaporator and in to the car.

 

I was under the impression that 134 is a higher pressure gas than r-12. If so, it does make sense to run less and see if the lower pressure allows the compressor to do its job. I actually have the A/C system completely dismantled in my Monte, as I have swapped in an LS2/4L65e. I will be running R-134 with the Sanden compressor I have for it.

 

Again, I can dismantle my brakes but this ac crap goes over my head! Lol.

Great! And shop said the compressor had a leak in the seal so that would need replacing anyway.. After a dye injection I didn't see any visible leaks, so hopefully with those parts replaced I can finally have a working ac

 

Fog on the windshield is usually a bad heater core.

As for locating an AC leak, the normal procedure is to pull the freon out of the system then charge it with 300 psi of nitrogen. You then go around with a soap/water sprayer and spray everything to look for bubbles. Seal connections, rubber hoses/crimps, along the seams of the condenser, all around the compressor. It could even be leaking from the cores in the charge ports. The hardest thing to check is the evaporator inside the heater box. unless the heater box is apart for easier access. A leak as bad as you're describing should be easy to find with soap bubbles.

If the soap bubble method can't find a leak then the system gets recharged and a freon sniffer is used to check the entire system. Once found, the system get evacuated again, repaired, recharged and rechecked as there may be more than one leak.

I love AC work. It's time consuming and a good money maker to diagnose and fix it right. Helps to have all the tools to do AC work. Electrical diagnostics is the same. Might tale 5 minutes, might take 5 hours.

 

AlkyIROC,


He mentioned having the heater core replaced 2 months ago. If he has a leak in the evap core, might oil in the AC system be condensing on the windshield...probably other glass as well, thus causing build up?

 

It's a possibility

 

It is, but very unlikely. I have no coolant loss, and the windshield only fogs when I have added freon and it takes a while for me to clean it off.

The one shop I took it to said to garuntee their work they would need to replace every component of the ac system.

 

If the evaporator has a two day leak, you'd definitely be able to smell refrigerant oil in the car.