A/C question for you HVAC guys. I've had a slow leak in my A/C for at least a year or so now. So I put some dye in it, and nothing shows anywhere. I have a sniffer, and the only place that sets it off, and then just barely, is on the interior vents. Today I got under the car, and though it's hard to see it, the chartreuse colored junk is under the 2 main lines (1 dual line connector with 1 bolt in the middle) at the rear of the compressor. I'm assuming the compressor can't leak at the rear EXCEPT where these lines attach. If that's the case, that's a BIG part of what is wrong. I always figured it was under the dash, in the evaporator unit. Maybe not!! I'm guessing here, but maybe I just need 2 new O-rings, or perhaps the single bolt has come slightly loose? I'm going to the Stealer in the next couple weeks to get the 2 new O-rings, and I'll find out then if the bolt has come loose. So, my question is:
Do you think it's possible that the escaping R134a could be drawn into the blower fan, thus blowing out the interior vents, and giving my sniffer the heads up? System gets ice cold, so it works well, before R134a leaks out after 3 to 4 weeks. Thanks guys.......

 

If im understanding this is behind the compressor the two lines that connect to compressor?? i used dye and i found mine was leaking under the compressor. Hard to see. I was banging my head to find it. If this is the area you're talking about.

 

On a friend of mine had a 2000 and blew one if the O-rings there. I just replaced those and all was good

 

Mine is apart right now, the compressor has been leaking oil for a while and wouldn't hold a charge. I have read many accounts of the compressor leaking, but not at the seals you're talking about. I bet you will end up replacing the compressor.

 

YES!! That's the area. And you're right-VERY hard to see much. Wish GM Engineers needed to work on this area!!! Instant design change!!! But yeah, that single bolted double line, the area underneath looks like green slime melted all over it! But, hard as it is, it beats Hell outta pulling the entire dash and changing the evaporator!! My sniffer has like 4 or 5 'stages' that the detect zone can read:
Super slow
Slow
Medium
Fast
Super fast
Since it is on the slowest stage of beeps, I'm thinking it's drawing residual 134a into the intake at the base of the windshield, then blowing it into the interior vents. Guess I'll buy the 2 O-rings, install them, pull a vacuum, recharge, andfor leaks, if any. My main concern is can the compressor leak anywhere else at the back other than that 2 line, 1 bolt connector? Thx Helga. I'll be in Hudson, Fl for the Winter. You're in Florida too, correct?

 

IDK, nothing at the front under or near the clutch. So.......

 

My car had that 2 line connector (manifold?) off the compressor for several years (LONG story!). I put it inside of a thick zip lock bag, and plugged the compressor to keep dirt out. But once those O-rings were disturbed by removing the connector, and exposed to hot header heat for several years, they may not seal well under high pressure. They were in place for almost 10 years, until some YAHOO shop reconnected them WITHOUT notifying me . Knowing the reputation of the now out-of-business shop, they probably reused the old O-rings, which are now 21 years old, and probably somewhat flat.......

 

I took my car to two different dealerships because of my ac leak. Both told me I needed a completely new ac system, compressor, etc. but they also told me they couldn’t find the leak. That told me they were using the shotgun method of repairs.

so I put a lot of dye into the system and bought myself a black light. In this pic you can see the dye leaking from the two o rings on the back of the compressor. Also with the car up in the air you can easily see the leak from the moisture coming out the back of the compressor. I spent about $9 for the o-rings and my buddy replaced them both in about 25 minutes. my AC has been perfect ever since. Don’t have any shop charge you more than an hour to replace those o-rings. I watched my buddy do it in 25 minutes.

 

No i,m stuck in chicago. The winters are getting tougher by the yr.

 

Your compressor has 6 possible leak paths:
1. The compressor body o ring joint to the front casting.
2. The compressor body o ring joint to the rear casting.
3 The teflon lip seal which has a leak path past the shaft and the o ring path between the lip seal housing and the front casting.
4. The manifold connection which uses two seal washers between the manifold and the rear casting.
5. The control valve o ring joint to the rear casting.
6. The high pressure relief valve o ring joint to the rear casting.

 

Thank you. So you're saying it may be several things at the rear of the compressor that could be leaking? I can see there's a considerable amount of dye under that double line/single bolt manifold. But what I can't see (yet) is if it's coming from above, or beside, that junction, or directly from it. FWIW, The wind generated by driving a thousand miles@75-80mph doesn't appear to have blown it anywhere, and it is definitely NOT coming from the front of the comsqueezer!!

 

Mike, I chased a Freon leak on my C5 for a number of years. Initially I just had the system recharged every couple of years and finally was adding a can of Freon about every 6 months. In the meantime I had three different shops put dye in the system as it was being charged to try and find the leak. I found it incredibly frustrating that despite the use of dye, we could not seem to find the source of the leak. I also replaced all of the pressure lines, including new O-rings and the orifice tube, to no effect.

Finally I took it to the most dependable shop I knew in the area and said, "you have got to find the leak." Here in eastern NC, the HVAC system in the C5 is pretty near useless without the A/C working much of the year because of heat and humidity.

They recharged the system and put it on the lift while operating and finally found that the compressor itself was leaking at the front seal. Interestingly while helping a friend at a body shop in the early 2000's I recall that we sold a lot of the GM compressors, new and used to folks trying to get their HVAC system working. Most however were higher mileage cars so I never really considered it since my car only has 40k on it. Also, the compressor is buried in the C5 making it more difficult to detect leaks than other cars and SUV's. In hindsight, I should have done a better job checking the compressor and I would have avoided a lot of aggravation, expense and discomfort.

My system has been functioning as new for the past 3 years.

Good luck... GUSTO

 

I just have a couple questions left. My 2 seals at the main ports at the rear of the compressor are leaking, badly!! It may be only 1 of them, don't know, don't care. I've ordered the "kit", containing both seals, from the Stealer for $11. Her are the questions:
Can I remove the single bolt holding those 2 lines to the compressor, without removing a lot of other stuff? I have 1-7/8" Kooks headers, which look like they restrict the access to the bolt. Have any of you had any success doing this, and if so, how did you gain access? Thanks guys......

 

yes. As I mentioned above. It’s a 20 minutes job.

 

Craig, you've been there-done that! I can tell!! How? I decided to drag my 67 year old fat *** out to the garage and give it a shot. It took 20-25 minutes, max. Or SHOULD have!!! First, I loosened the collector on passenger side so header could swing towards, and away, from the cylinder head. Then removed the header bolts, and put a good strong bungee strap thru a couple header mounting holes, one on each end, to hold the header up where I needed it to be. The idiots (see earlier post!) at the shop that put it back together used a non standard bolt, so it took a 17mm socket instead of the 15mm socket it should've taken. It gets better (worse for me!!). It's an M10 bolt, so they used a lock washer for a 1/2" bolt (!), then used RED LOCTITE () on the damn thing!!! DOH!!!!!! That bolt would've NEVER come loose on it's own, trust me!! Anyway, I used a 3 foot long piece of stainless steel thick wall tubing as a breaker bar, and some heat to finally remove it. I have the original, correct bolt to reassemble, and will-MAYBE-Use a dab of blue loctite on it. There was no dye anywhere else on the compressor, so I think these 2 new seals might do the trick. Fingers crossed 🤞, and thanks to everyone who helped. I'll post up if these seals do the job, or not....

 

So you had the car up in the air and turned the wheel to the left and accessed the compressor from the bottom? I watched my buddy do this and I don’t remember the headers being in the way. Not sure though. I was drinking beer. 😂😂🤣

 

on the beer!! No, I accessed the compressor from the top. I just lifted and swung the headers out of the way enough to access that damn bolt at the rear of the compressor that holds the lines on. Picked up the new seals, installed both, tightened the bolt, and I'm pulling the vacuum now. So far, gauge says almost -30hg/in (OK, not sure if my memory is good on the terminology...). I'm going out in 15 minutes, and if all is well, headers are going back on, 134a going in, and I'll hopefully have A/C with no leaks and cold air! Time will tell, and yes, a 21 year old compressor is on borrowed time, for sure. We'll see if I can get another couple years out of it. I'll post up more info, good or bad. If I end up having to recharge in a month, then Ive gained nothing, out $22.00, and a little work. 🤞

 

Should have gone up from the bottom. Much easier. Nevertheless, these compressors are actually really strong. Should have no problem lasting longer than 30 years. Don’t let the internet bring you down.

 

While you’re system has no charge, it’s a good idea to go around and replace every single o-ring in the system. They can be picked up at the hardware store. Don’t waste a charge!

 

I don't know how much easier with the headers. Anyway, I don't think it was too bad to get to that bolt in less than a half hour. If I was going to do it again, I could probably do the whole seal removal and replace in an hour, and another half hour to finish the exhaust. I'm happy with my time. Its all together, and ready to recharge. Right now, I need a recharge!! But I'm also open to better/easier ways to do anything. How would you do it from the bottom? Are you doing this with OEM exhaust, or headers? I can't even see anything from the bottom...