I've got an 80 that has been sitting undriven for most of the past 2 years. I only got to drive it when I was in town visiting my folks. Last time I was there, the A/C was not blowing cold air. My question is do you guys think this is a simple case of the A/C needing to be charged, or is there something else going on here. I'm moving back in May, and I don't want to drive back to Dallas with no A/C. Little Jake gave me a shop to take it to, but I want to go prepared with ideas of what it could be. I may have my brother take it in for me if it could be a bigger problem that can't be fixed in a day (I've only got a week in Nashville to get it fixed). Thanks

 

I have a 77 and my A/C system is out now for rebuilding for the expected HOT summer. From what "I think" I have learned thus far -freon doesnt evaporate in a closed system. So If its lost its cool perhaps there is a leaky o ring/fitting, condensor, dryer or evaporator. hoses or a sensor has failed or the compressor has pooped out. So far my condensor has tested good and I'm rebuilding the dryer. The evaporator is being tested this week. I think my problem was a leaky "O-ring" but I too stupid to just fix that so I pulled it all out to rebuild.

I understand a system can be flushed and pressurized to check for leaks and that at least you'll be able to tell where its comming from.
But FYI there are at least 1/2 dozen places for failure.

The hood has to come off to get to the fittings and get the condensor off if necessary. Geting the evaporator off the fire wall is no easy task either. For somebody who knows what theyre doing, and has all the parts on hand, I would still think they'd be hard pressed to get a overall rebuild done in 2 days. I've putzed with this for 3 weeks most of it in waiting for parts as I dont order until I'm sure I need it.

You probably still have r12 in there too.

I think, if I were you, I'd just let them pressurize it to see whats up.
Maybe its just a lousy o-ring?

 

Man, I really hope it's just an o-ring. Otherwise, I'm going without A/C this summer (in Dallas) until I can afford to fix it.

 

If it was working before that, then most likely it needs some more freon or possibly a hose (more likely than an o-ring).

 

An A/C compressor, sitting in one position for a couple of years, is a good 'recipe' for freon to leak out. Since it was working before you parked it, it is probably OK now (unless there was already a small leak working). Charge it up and drive it a while, then try it out. It should work...the only question is, "For how long?". Good luck.

 

If the car has been sitting for a couple of years it is not uncommon for your system to fail, especially in a hot climate. The rubber o rings and even the hoses will deteriorate and your freon will leak out. If your compressor comes on it's most likely a leak, but it can be an easy or difficult fix, depending on what's leaking. You can have a shop charge it up and run a can of leak detector through it, that's the easiest way to find the leak. If R12 wasn't so expensive I would just charge it up and hope that fixes it, but I would hate to replace it twice.

 

The difficulty is that you have to put some fluid/lubricant in the system before you can know whether it will seal or not. You could put a vacuum to it, but since it has been sitting so long, it's not a surprise that it leaks. Maybe you just put a light charge in the system so that you can exercise it to get it re-sealed. Then have it evacuated and tested for leakage. If it seals OK, fill it competely and it should be OK. If it still leaks, have a pro figure out the problem.

 

I have an 80 and I just replaced my A/C this past weekend. Mine was all original and it had a leak in the compressor. I just decided to change out the system and go R134.

I purchased the kit for $259.99 plus $35 shipping and it came with the compressor, drier, orfice, seals/o-rings and oil. Many corvette sites sell the kit, but I got mine from EBay seller from Texas. Here is the site if you are interested:
http://stores.ebay.com/airpartsstore...QQftidZ2QQtZkm

My friend and I replace the system in about 3 hours. It was really easier than I thought. My friend was the expert, but let me do the work so I could learn. I'm sure he could have done it in 2 hours.

The hardest part was changing the drier, but by removing the gills on the side of the car, it was easy to get to the bottom of the drier. We took all the breather components and the anti-freeze overflow bottle out in order to get to the drier.

I purchased the R134 and taking it to another friend this weekend to vacuum the system then load her up.

It pays to have good friends.

Basically what I'm saying is if you have someone who knows what they are doing, it's not that expensive to replace your system.

Good Luck