I have had my '99 C5 Coupe since 2010. Purchased it from a forum member right here in the Corvette Forum C5 for sale section. Its been a great car although I don't put many miles on it. It has just a little over 37k miles on it. Since I got the car I have been putting about a 12oz can of Freon in it every year during the Spring and I was good through the Summer. Now it only lasts me a month. The Compressor is good but I have a leak somewhere. My question are there certain areas on the C5 where I should look first for bad rubber O-Rings? Was under the car and can see a slight drip of what looks to be compressor oil under the compressor. I put a can of dye in the system and used one of those lights and it looks like the whole Compressor Glows in the special light. So I am guessing it is around the compressor area but unlike older cars I have worked on years back access to the compressor is not so easy anymore. Just curious what other members recommend me looking at or possibly trying. I should mention although it probably makes no difference I have the standard Hvac Sytem with the 2 dials to dial in my A/C through the dash. That is not the problem though. My leak is somewhere under the hood possibly right at the A/C Compressor. Any Ideas?

 

Moved to C5 Tech.

 

Quite possibly leaking at the split in the compressor housing. It's a common issue.

 

To find the leak here is a decent "how-to" video

For the 99 car AC performance, see my post is this thread https://www.corvetteforum.com/forums...99-no-a-c.html

Cheers,
Goose

 

Now that is something I didn't know about. I like to be sure before I order a new compressor. Awhile back I looked at a video on You Tube being I was curious how much trouble it was to take a Compressor out of a C5. I see one fellow did it without taking the Water Pump down. Don't know if I want to take this job on but I have done plenty of things in the past with A/C Systems. That is why for the last 10 years when it came to just adding a can of R134A once a year I took the easy way out. I very rarely send my cars out for work to be done to them. I guess I can't really complain that one can a year nursed the car for 10 years. Are their any other directions either written or other good video's out there on doing the job anyone would like to share? My main concern is getting it out of the car and installing a new one. Not worried about filling it and vacuuming it down. I have what I need to do the job. I wish I could be sure it is the compressor leaking and not a oring behind it where the A/C hose manifold connects which I believe is hidden from view. Its been months since I last looked up under there. Just wanted to check on the forum to see what others who faced this situation went through.

 

I paid someone else to change my compressor, they did it without pulling the pump -- though I was on business travel and didn't see how it was accomplished. That center case seal has been noted to be a leak source several times. Before I paid someone else, I got a leak detection kit with blacklight pen, glasses, and refridgerent with dye. My seal may have been worse then most, but all I found with the kit was a lot of leakage below the compressor. Not a lot of other leak paths there, so extrapolated it must be the compressor.
This month's Harbor Freight coupon book has the A/C gage set for $40 or so. Hard bargain to pass up.

 

Water pump removal and installation is not a difficult task. I would not attempt raising the engine although others have had success. The two lower bolts holding the compressor are easily accessed with the wheel removed. The other two, obviously, from above. With the hoses, belts, and water pump removed, you will be surprised at how easily it is to remove the compressor. I used a long extension and universal to remove the manifold bolt prior to loosening the four aforementioned bolts. I'm sure that someone here can chime in with a step by step procedure.

 

Yes that is a good price for someone. I have a set of both R134A and set of R12/R22 gauges plus a electric Vacuum pump from much A/C work I have done in the past. I am going to throw another can of R134A in and put it up on my lift in my pole barn to take another look at it. It really isn’t something I am going to feel like tackling during the Summer Time and almost July. When I was younger nothing would of stopped me. Just for the heck of it if you don’t mine me asking. What did they charge you to change your compressor out? Your situation (Leakage right at the compressor) sounds like my problem. With the dye and light the only glow I saw was at the compressor. Where did you get your compressor from? Did you go new or rebuilt? I have seen rebuilt ones on line from $129.95 on up. New ones from $170 on up.

 

Rock Auto would be a good place to source the compressor

 

There compressor has 7 possible leak paths
1. There are two large diameter body o-rings
2. There are two seal washers at the hose manifold To rear head connection
3. The control valve located in the read head of the compressor
4. The high pressure relief valve located in the rear head
5. The lip seal in the front head.

and the castings themselves of course but that is pretty unlikely to just suddenly get worse.

It should be easy to eliminate the lip seal. If it is leaking, you will see compressor oil dripping from the a/c clutch face and the pulley will be slinging oil. To narrow it down any further than that the dye should be giving you a good visual indication. If it’s from the body o rings the dye and oil should be gathering around the joint between the compressor cylinder and either the front or rear head. If the dye seems to only be on the rear head than it is 2, 3, or 4 from the list above.

 

I don’t use or recommend Rock Auto for anything anymore. They tried to burn me on a defective front Monroe Strut on my wife’s car about 3 years ago. Less then a month old the top bearing on the passenger side Strut went bad. The other 3 Struts were fine on the car. They would not pick up the defect or send me out a new Strut to replace it. At that point I had to dispute the charge with my Credit Card Company. I won my case and Rock Auto still didn’t make good so the Credit Card Company pulled back the money on the one defective Strut and I purchased one elsewhere. Long story short a year later I thought I would give them another chance and tried to buy something from them. The order went through and a couple days later I got a email from Rock saying that they can’t sell me the item because I owe them money which I don’t. My name and address is on their Black List. My daughter tried to buy something from them last year and they stopped and cancelled her order being she lives at the same address. There are plenty of complaints from others who have delt with Rock Auto on You Tube for those who may want to check it out. I once thought they were good to deal with spending a couple of thousand dollars with them over the years but like others said on You Tube that changed.

 

The last time I checked with the special light the complete compressor glowed making it hard to see where it is coming from.

 

I decided to order a Brand New Compressor last night. I believe the Compressor is leaking somewhere in the body of it. Time wise and what is involved with replacing the Compressor I decided to go with a brand new one although my original with only 37k miles on it but 21 years old is working fine. I will put that one on the shelf knowing it is good except it leaks and buying a brand new one doesn't require you to hand in a CORE.I will have to see how much a complete seal kit will cost for it for the heck of it. Will come back to this post eventually after I get the job done replacing it with a new one hopefully when the weather gets cooler out. Lately 95 degrees and humid as can be I can't handle working in that kind of weather 8 months away from turning 70 years old.

 

I created this video awhile back showing complete hvac replacement on c5. It is a big job, but technically the compresor is the easiest part if that means anything.

Good luck!
​​​

 

This is one of those jobs where paying someone else to do the labor is worth every single penny. Sure, sure, it always better to do it yourself -- never delegate is my rule #4. None the less, a good A/C shop will have the job done in less time than you will spend getting ready. Plus, most shops will work with parts you bring with you, and will have parts you don't know you need yet (Schrader valves, etc.).
Regardless, don't forget new receiver/dryer and orifice tube to go with the compressor -- its warranty will require you to change both.

 

The new Compressor I purchased is coming with everything I need including a ortifice tube which looks very familliar to me being I use to sell them in my Auto Parts business I retired from in 2012. It also comes with a new dryer and pag oil. Being the compressor hasn't really gone bad and A/C even now goes down to 39 degrees with the can I just added when checking for leaks I don't believe there is any blockage in my system at 37k miles so I may just skip replacing the dryer and ortifice tube for the time being and just add the needed PAG oil to the new Compressor and install it and Vacuum the system down. I am not new to working on Automotive A/C. Have worked on many even installing A/C in my Street Rod when I built it during the 90's and a Chevy Pickup Truck that never had A/C to begin with years ago so the job doesn't scare me. I very seldom send work out unless I know I can't handled it. My concern was how I was going to get this compressor out and in more then anything else but my research shows me I can do it without taking the water pump off the car by jacking the engine up a bit on the passenger side and disconnecting the hose going to the Stat housing and taking off the stat housing and heater hoses from the engine.

.

 

My 97 C5 few weeks ago was covered with green fluid on bottom of the top inlet water pump neck, compressor clutch, idler pulleys. I thought it was water pump thinking that green liquid is coolant but upon detailed inspection it was leaking from front of the compressor inside the ac clutch. I hooked up portable ac charge gauge after using the ac for a week. The ac hauage needle is at yellow which indicated ac is good no refill needed. My ac is currently working fine but i haven't visually inspected to see more leaked out. Oh also when i pushed in the ac clutch at the top it is tilting in so the clutch is loose and moving in and out. Can you conform leak is from cmpressor at front ? I'm guessing green liquid is theac comp. Oil?

 

GM/Delphi Compressor oil in 1997 definitely was not green. The factory oil is clear if I recall correctly and turns a little brown over time with use. I think you may have mentioned “dye” in an earlier posting. Typically dye for leak detection requires a black light to see it. Did someone put a leak detecting fluid in the a/c system that does not require a black light? If you were weeping compressor oil past the lip seal, I would expect to see a drop or 2 collecting at the bottom of the pulley face after the car sits for a day or 2.

what you are describing about the clutch “tilting” sounds normal. The clutch is separated from the pulley face by about 0.040” and suspended by 3 leaf springs. If you push it with a finger, it will move fairly easily until it contacts the pulley face.

 

I purchased a cheap A/C Dye kit on Ebay a year or so ago just to check out my '99 Coupe being I have been putting a 12oz can of R134A into the system every Spring for just about the last 10 years. It would last to the next year being I didn't drive the car during the winter. Last year I put it up on my lift after putting a can of R134A Sealer with dye in the system. The color of the DYE was red based on what I saw left in the remainder of the 2oz or so can. I use to sell this product in my Parts business years ago and had a left over case of 12 cans. Shops were buying it and some had good results with it but not everyone. The sealer supposedly makes any non broken orings expand to seal leaks. Anyway it didn't work in my car but as I mentioned it also shot dye into the system which worked very well with the Cheap Kit UV light kit I purchased. I shined that light over every place I would expect a leak and found nothing. When I put the car up on my lift as you all know you can't see very much of the compressor being the Front Spring is in the way but shining the light on it the compressor lit up like a Christmas tree but nothing showed in the front clutch area. Let the car down and shined the UV Light looking down in the area of the motor and saw the same. I couldn't see much more. Having added the can of freon and getting readings at around 39 degree's I just let it go for the time being. This Spring I had to add another can in the Spring the 1st week of May 2020. Back to 39 Degree's. I keep a large A/C dial in the top Vent of this car to keep checks on it for a few years now. Well this time that charge only lasted to the end of June. Have done quite a bit of Research here and elsewhere and after taking the front passenger wheel off with my car on the lift and shining that same UV light on the Compressor I could see that almost the full body of the compressor shows the lit up dye through the wheel well. I was kind of hoping the problem might of been coming from the back A/C Hose Manifold leaking. Based on my knowledge I gained of the years doing all my car A/C work going back to the 70's there wasn't much residue back there that indicated that as was on the main body of the compressor with the UV light shining on the compressor. I then thought being the A/C System was filled and had very good pressure let me try the old way of checking for leaks with a Spray Bottle and Dish detergent a 50/50 mix. Sprayed it all over the Compressor yet I saw no bubbles forming anywhere on it. Also sprayed everything else that could possibly be leaking and saw nothing just like the UV light showed. So I believe my compressor is the culprit just by what the UV Light and Dye showed me and ordered a brand new one. For a matter of fact it was just delivered to me and my car is still sitting on my lift in my Poll Barn. Don't know when I will get to it. At my age 8 months away from turning 70 I don't like to work in very hot humid weather if at all possible anymore. If I was 19 again nothing would stop me. So I am playing it by ear as to when I pull it out of the car and replace and vacuum the new one down and refill it. Still not sure how much pag oil to put in the compressor. I have heard all different amounts from people. The company that sells the compressor told me 9 ounces. Others have told me 2-3 ounces. Some say empty your old compressor out and put back in the same amount into the new one. My concern with that answer is that I don't know how much compressor oil I might of lost over the years because it did drip oil slowing on to the Front Spring red in color. It looked almost like the color of motor oil before I added the dye.

Add on: Being my old compressor is still good other then leaking probably from the body of it I am just curious if anyone knows where and how much it cost for a complete kit to reseal this compressor being it is not frozen and actually works well. This new one I purchased may actually out live me but I plan on putting my old one on the shelf in case I ever need a replacement clutch or something else from it being it is coming off a car with 37k miles on it. Really how bad can it be? Say that kit of compressor seals cost $20 it may be worth it. I just saw since I purchased my compressor less then a week ago a few places raised the price up on the same compressor kit better then $120 more. That is Unreal.

 

Oil balance compressor only change: Old compressor. remove the crankcase oil bolt and drain. Drain from the suction/discharge ports too. Measure it. New compressor: drain it. Then add the amount of oil you drained from the old one back into the new one. If it was my car, I would probably add 2 ounces. I would NOT add 9 ounces.

I am not aware of anyone who sells a rebuild kit for a Delphi V7 compressor. I no longer have any information for the dimensions of the 2 body Orings so these are only approximate:
Inside diameter 117mm
Cross section: 5.1mm

The material is HNBR I think. Don’t worry if you find some and they are not green. We went to green color back when we converted to R134a so we could see the difference in manufacturing.

if you’ve disassembled compressors in the past you know you will need service tools to remove the clutch, pulley, and lip seal.