My AC Battle

Thought I would write up what I have done to my AC to get it mostly functional.

I have an 84 NA, when I got the car the defrost was stuck on. This became pretty inconvenient once it started warming up in Texas. I ordered a new aspirator fan from Courtesy and installed it. That fixed the vent issue, but the AC Gas light was on. A friend of mine has a set of AC gauges and is pretty good with that stuff, so he hooked it up and checked it. The car was registering 8lbs (of R12). I drove the car for a couple of more weeks and checked it again and it still had 8lbs in it. This gave us hope that there wasn't a major leak. The car had been pretty much just sitting with the PO for about 8 years, so I was hoping that was the cause. R12 is pretty expensive now and hard to find. I decided to switch the car over to R134a. We pulled a vacuum on the system for 30-40 minutes and checked the gauges for leaks. It was holding a vacuum, giving us the impression that there wasn't any. Since the system hadn't been open and exposed to the environment, we went ahead and put 2 cans of refrigerant in along with the necessary oil. The system was still not completely full, but was cooling. During this same time I was having problems with the vent doors not staying closed under load or just flat out not going where they were supposed to be. Sometimes, when I accelerated they would go to defrost with the heat on and not come back to the vents. Sometimes it would stay at the vents if the fan was on low, but hi would have enough force to push the door open a little and I wouldn't get air from the defrost or the vents. After reading here and the other sites I started looking at the lines coming off the tank. I replaced all the vacuum lines and that helped some, but still had the defrost issue under load. I started looking for pictures of the tank with labels, the diagram on the FSM wasn't quite clear enough for me. I found the picture I needed at http://www.88hybrid.com/vaclines/vaclines.htm, it's the one of the 85T vacuum tank. Hooked my lines up like that and that made everything almost perfect. Under normal acceleration the vents stay blowing, under heavy load, they will still get weak and/or blow warm air. It is very livable now. I have a thermometer in the vent and the air coming out is usually between 42 and 48 degrees.

This is just an account of what I have done to mine and is no way a definitive guide. The refrigerant I used was synthetic R134a called Artic Freeze (I believe) from O'Reilly's, it was around $20 per can. I used 2 cans of it and topped the system off with about 1/4 to 1/3 of regular R134a. Normally, you are told to change the seals, the oil in the compressor and the dryer when you do this change. Like I said, since the system hadn't been open and seemed to be holding some charge, I skipped it. I suspect a new compressor my be in my future, the system doesn't cool as well as it should sitting at a light. When that time comes, I will most certainly do the full change. The dryer is only about $20 and the seals are around $12. The compressor is around $270 at O'reilly's.

I haven't changed the vac lines under the dash yet, that could be another source of my problem or weak/leaky actuators. When I take the dashboard out to be replaced or redone, I will put new lines in on all the solenoids and actuators. Hopefully this will help someone.

Edit, as is pretty readily found, NA cars have the cruise control line running off the intake. Turbo cars have an electric vacuum can under the vacuum tank that runs all the accessory vacuum, so the cruise line is connected to the very top port on the tank. I just capped mine off with a piece of hose with a screw in it.