I've read through many posts on Air Conditioning issues and am asking for a little help with my AC. I've got 65k miles on an '00 Coupe and am the original owner. A few days ago I saw a puddle of oil under the car and assumed it was engine oil (same color & texture). A few days later, I noticed the AC blowing cold, then hot, then cold. After looking things over, I think the oil is from the AC (ester oil?) and the leak is from the inlet port on the back of the compressor. See photos.

If that's all it is, then I just want to remove the single bolt, change the O-rings, bolt it back together, evacuate, and re-charge (total cost ~$100+ time 1-2 hrs). The alternative is a complete rebuild including drain the radiator, remove the water pump -- you know the drill.

Here's the question: Is it likely that the problem is leaking O-Rings on the back of the compressor? Has anyone else had this problem? I don't see evidence of any other leak.

I remember a comment by Bill Curlee's saying that these AC compressors tend to be reliable if treated properly. If I can go another couple of years before a major issue, I'm good.

Thanks for making this such a great forum.

Dave

 

From the service manual directions on how to replace the hose it looks like you can do it without pulling the water pump. However, you will have to be able to get the car up in the air and the compressor bolts will have to removed so you can move the compressor forward. If you send me a PM with your e-mail address I can forward a MS Word document with hose replacement instructions.

Bill

 

Common problem on C5s. If you're a lot luckier than I it might be just a loose bolt. It's cheap enough to give it a try.

If the seal in the middle of the comp is the culprit then you're stuck with a comp replacement. You could also shoot some dye in it to verify the leak.

I would try the seals at the back first. BTW, it's not an oring, it's kind of a flat alum washer with a rubber insert.

Available from the dealer or any good FLAPS. Good luck

 

quote-, I think the oil is from the AC (ester oil?) and the leak is from the inlet port on the back of the compressor. quote.
Hi, the only thing I would add to the others advice is the oil is PAG oil. Cars that have been retrofitted from R12, to R134a use ester oil because it is universal and will mix with both poe and pag oils, and still provide adequate lubrication.
The c5 always had R134a from the factory and uses PAG oil which is better for it, and less hygroscopic.
Good Luck

 

I think the fix of just replacing the seals on the lineset worked. I can't detect any leaks and the AC is blowing 40F in 85 degree weather with 60% RH (better than spec). If the seals hold, I will have saved a lot of money over a complete rebuild - less than $100 vs >$1000.

A few tricks for those in a similar predicament. Only one 13mm bolt holds the two hoses (lineset) to the back of the air compressor. It is a bugger to get to. I ended up using a 13mm socket + swivel + 6" extension + 1" extension and working from under the car. If you have a combo swivel/socket, it would be better. As exciting as it is getting the bolt out, putting it back in and estimating 19 lb-ft of torque with the swivel at an angle is even more fun. The way I estimated the tightness was by feeling 19 lb-ft with a bench vise & torque wrench - then getting under the car and getting the same feel.

I planned to unbolt the lineset and quickly pull it back, then cap the ends, put on new seals and bolt it back together. That didn't work. There is no way to get easy access to that area. Fortunately both hoses have rubber somewhere in the line so it is possible to pull them back from the compressor about 2". That is just enough to get a couple of fingers in there and push on the seals. For me, the operation took about 10 minutes from unbolt to re-bolt and torqued.

I cheaped out in buying a vacuum pump from Harbor Freight. For $13, I get 28.3" of mercury vacuum (30 ideal) - see item 96677-6VGA - at least that's what advertisement says. I hooked up the vacuum pump through a manifold gauge set and it looked like I was only pulling about 20" of hg. I've got a pretty good shop compressor driving the vacuum pump, so it did keep up with the CFM required at 75 psi.

Given the humid FL weather, my cheap vacuum pump, 10 minutes of an opened system, and another 15 minutes of drawing a marginal vacuum, I'm sure there was some residual moisture in the system somewhere. That said, I figure the dryer is in the system for a reason, so let's use a little of it. Besides, if I get a few more years of AC on the Vette before the pump dies for $100, I'm well satisfied.

On the other hand, if my AC dies in the next few months, I'll fess up and post an update to save others the embarassment.

 

Got the exact same thing on my 98 with 72k miles. Had to crank up the ac and put soap bubbles to find the leak, where the manifold meets the compressor, lower passenger side.

NAPA has some ac kits for Corvette, can't tell if it's what I need though, where did you get yours, and maybe a part number? Did you add oil?

 

FL_Dave,

Those are some excellent pictures of the bolt holding the manifold to the AC compressor. I replaced my compressor in October of 09 and now I have PAG 46 on my garage floor and no AC. I am going to replace the seals at the compressor/manifold interface and see if that fixes the problem.

I found a AC Delco document that calls out the AC o-rings and sealing washers. The seals are Delco 15-31101/GM 2724966, 1/2 o-rings Delco 15-32516/GM 52454645, 3/4 o-ring Delco 15-3985/GM 52454646. You'll need two 3/4 and three 1/2 o-rings. The sealing washers usually come with a new compressor, you'll need two.

http://www.acdelco.com/pdf/appcat_bu..._snaprings.pdf

Here is a good view of the AC system:

http://www.gmpartsgiant.com/online/P...exID=1Y0904501

Paul

 

excellent thread. bookmarked