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90 Chevrolet Camaro AC


samwise's Avatar
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09-09-03, 07:00 PM   #1  
samwise
90 Chevrolet Camaro AC

Here we go again. Just changed the water pump on this vehicle recently, and it's working fine. The engine was tuned up within the last couple of months. Now the AC compressor is making a noise when the compressor clutch engages, and it's not cooling at all. In fact, the air is kinda hot when it blows out.

I'm a do it yourselfer who has access to the tools/materials needed to work on this system. I have experience with my 82 Camaro, I completely changed the AC system (including hoses, drying chamber, compressor and belts) with the supervision of a friend who is no longer in the area. He recommended I change that whole system due to the age of the car.

Given the symptoms: 1. clutch makes noise when it engages 2.no cool air 3. there seems to be a larger than usual puddle of water under the front of the car after the AC runs; Is there anything else I need to evaluate to help make the diagnosis?

I'm vaguely familar with the entire process, and would probably need to consult a manual if I took this on myself. I'm currently weighing the options of taking the car in to get worked on, or doing the work myself. Any advice/comments you have would be appreciated, as well as recommendations for a complete resource/manual that would cover the procedure in detail.

Thanks in advance

Sam

 
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09-10-03, 04:11 AM   #2  
Joe_F
If you can cajole your friend into helping you, this would be the best thing.

A/C repair is not DIY without ALL the tools and procedures to service it.

Minimally,you will need a vacuum pump, gauges, leak detector as well as the proper service information. This stuff will run you several hundred dollars.

If you can convince your friend to supervise you and he has the experience and tools, it's a worth endeavor in my belief.

Converting the A/C on this car to R134A (if that's your intention) will also cost a few bucks in parts, depending on how and where you buy your stuff.

I repaired a couple of A/C systems this summer for low cost, but my situation is a little different than most with regard to cost and tools and equipment .

 
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09-10-03, 06:10 AM   #3  
The larger than normal water coming from the evaporater drain is not consistant with an a/c failure, in fact, that means it is doing it's job. Perhaps it is more humid now? Additionally, a noisey compressor also does not make for a failed system. Depends on how noisey I guess. If the compressor has indeed suffered catastrophic damage, the orifice in the liquid line to the evaporator would need to be inspected for debris. But having a set of gauges on it and knowing what the pressures are would be a good thing.

 
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09-10-03, 07:23 AM   #4  
I think that step 1 would be to rent a set of gauges from AutoZone and see what's happening when you engage the compressor. Let us know what your readings are. Be sure to note the ambiant temp when you take your readings.

 
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09-14-03, 08:32 PM   #5  
samwise
thanks

Joe>> Asking him to help me is out of the question right now, he's over in Kuwait, and even bringing it up in conversation seems inappropriate. "...This stuff will run you several hundred dollars." Even if I only rent the equipment? I was considering purchasing at least the guages as they seem vital to not only repair but also maintenance and diagnostics. What do you think? If you were going to put down some cash, would it be on the guages?

BigGuy>>"The larger than normal water coming from the evaporater drain is not consistant with an a/c failure" Now that you mention it, I see your point. "Additionally, a noisey compressor also does not make for a failed system" Well, let me be more specific. I think the noise is the clutch, and when it engages, it makes a rough non-whiney noise that sounds like metal grinding. I was thinking maybe the lubricant leaked out and now that somehow has led to a clutch malfunction. I'm reaching as my understanding of inner workings of the compressor are very limited. Anyway, that's the noise, I'm almost sure it's indicating malfunction, but you're correct, whether it's compressor malfunction and whether that is leading to A/C failure is definitley still unkown. "If the compressor has indeed suffered catastrophic damage, the orifice in the liquid line to the evaporator would need to be inspected for debris." Care to expand on this statement. I kinda know what you mean, but more detail would be greatly appreciated.

Dirty Dan>> Thanks bro, that's exactly what I'll do. Will check back when I have that info for you guys.

Thanks again guys, and I would also appreciate any input for this question I posted earlier "...for a complete resource/manual that would cover the procedure in detail."

Peace

 
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09-14-03, 10:02 PM   #6  
mike from nj
<<<Thanks again guys, and I would also appreciate any input for this question I posted earlier "...for a complete resource/manual that would cover the procedure in detail.">>>>
that's called the factory service manual, expensive but worth it, or try the manuals at the local library, stay away from the haynes or chiltons manuals

i'd be surprised if anyone would rent a/c gauges, too much liability. you would have a better chance finding them for sale(online), as almost every shop isn't allowed to use them anymore, recycling machines must be used nowadays.

lubricant almost always leaks out WITH the freon only, usually the freon is long gone while the oil remains in the system, i've(rarely) seen noisy compressors quiet right up when oil is injected into the system---not always. some systems develop a drone that transmits through the lines into the passenger compartment, not to be confused with a noisy compressor, broken or missing bolts causes that.

if the larger hose going to the a/c compressor is cold, it's a good bet that everything is working, that's an easy thing to check.

also, don't forget the clutch has a bearing that can make peculiar noises, usually all the time the engine is running though, you can look for brown rust around the front of the compressor when these go bad---not always (again)

just my few opinions/observations

 
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09-15-03, 06:48 AM   #7  
Joe_F
The factory service manual in this case is only a GUIDE because when it was written in 1989/1990 this car had R12. Things have changed a little bit.

Unless you want to keep it "OEM", you're going to be doing an R134A conversion. This involves a little more homework as each car varies with what is required. The parts supplier (such as AC Delco) may be able to recommend what should be replaced, but at minimum:

All O-rings
A/c hoses.
Oil flush
Receiver dryer..

Some vehicles require more. I keep all my R12 cars R12 or a blend of the same (a whole other topic).

Really think this one through and perhaps wait it out for your friend with the correct knowledge. You can easily do this job twice if you do it wrong the first time.

 
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09-15-03, 07:02 AM   #8  
Well, the factory manual I think would stillbe the best choice, except for the part about what the refrigerant is.
When the clutch engages, does the middle part of the clutch hub start to spin? The part I am talking about should be stationary, engine running, a/c shut off, and it should spin aat the same speed as t;he pulley when it engages. This can all be serviced without discharging the system, removing the fan shroud and/or unbolting the compressorr from it's mount might be needed to access the clutch. Special tools are required to service an a/c clutc h, by the way....

 
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09-15-03, 07:35 PM   #9  
samwise
Hold the presses

Ok, remember, I'm a novice do it yourselfer. I borrowed a set of manifold guages to check the pressures. The connections didn't fit, can you guess why? Well I was floored, so I consulted a binder that had documentation of every oil change/service/repair etc (it's a big binder). This, in fact, is the most well recorded car I've ever come across. It appears that around 96 the AC was converted to r134a. It appearantly was done correctly because the A/C system worked great until a couple of weeks ago. At any rate, the conversion is already done. Woo Hoo.

Now the prob with the compressor. The clutch engages, but then it seems to slip/stick and slows down slower than the speed of the belt. In other words, with the A/C on and the clutch engaged, the clutch appears to stick which causes it to slow down and stop intermittently. If I had to guess at this point, I would say the clutch needs some service, but would it be worth it to just change out the clutch, or is that part servicable/rebuildable (sp?)?

I'm going to try to get my hands on a set of manifold guages for r134a system. I saw a set at Ebay once for like $60 USD. Is that a pretty good deal?

Looks like I'll be relying the public library for my resources, priced the factory book, it's not cheap.

Thanks again to all who have helped, I really appreciate you guys and this site.

Peace

 
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09-16-03, 12:09 AM   #10  
mike from nj
sounds like a slipping clutch, sometimes they even make sparks!

oil on the clutch surfaces will cause this, it can only come from a leaky front seal. also, i think the clutch gap is adjustable, but you need specific tools for that, sometimes the electric coil underneath is weak or melted or burnt up, that you can sometimes smell.

try measuring the air gap, if it's too big, you will have this problem


the worst case scenario is a compressor starting to seize up.

 
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09-16-03, 03:42 AM   #11  
Joe_F
Yes, the factory book isn't cheap. If you have to squibble about the price of it, this 'ain't' a job for you .

A/C systems are dangerous. You need the right information to service it. As I mentioned, Ebay has those books cheap. Shoot, I paid $15 for the GM manual for my Cavalier. A Chilton or Haynes will cost you that! LOL.

The factory book has good information on theory of operation, troubleshooting, maintenance, repair and good pictures. It's not a niciety, it's a requirement here.

60 for a gauge set is OK depending on who makes them.

 
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09-16-03, 07:15 AM   #12  
samwise
Hey Mike. The clutch isn't sparking, but it's definitely sticking/slipping. I can turn it when the car is off, this is normal, right?. I failed to mention that I recently had an Antifreeze leak from the heater control valve, and some of this may have gotten on the clutch. In retrospect, the timing of that leak seems to coinside with the timing of the AC problem. Related? Perhaps. I don't smell anything burning around the compressor, nor are there any visible leaks. Will definitely check the air gap.

Joe, bro! "this 'ain't' a job for you " You assume too much my friend!
I squibble about the price of everything, especially if the resource is available at the library. Haven't checked yet, but the university I teach at has an automotive program, and I'm sure they have the literature I need. Don't count me out just cause I'm not going to pay $70 for a book. That's how much a guy quoted me over the phone. Hell, I have a pHD in pharmaceutical sciences, and don't honestly remember the last time I bought a book! LOL
"A/C systems are dangerous." With all due respect, so is driving a car, mowing the yard, changing a water heater, replacing torsion springs on my garage door, jacking my car up and getting underneath it, pissing my wife off, and yet I live to tell the tale! Look, I know it's dangerous/a challenge, but that's why I'm here brother, and your guidance is invaluable! The guages are reconditioned and are made by Interdynamics Inc.

Next on the list is to determine the pressures and measure the air gap.

Thanks again

Peace

 
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09-16-03, 07:24 AM   #13  
Joe_F
It scares me that you don't use manuals to guide you!

Read, read, read. Trust me, GM knows this car better than all of us, they made it.

I haven't paid 70 bucks for a SET of my service manuals, EVER, never mind one!

I've seen these things go for 15 bucks on Ebay, sometimes less. Read, read, read, read, read.

I'm "value oriented" too, but this is a small price to pay for doing it right and perhaps your safety as well as the integrity of the system. A/C repair ain't for the faint of heart and it ain't for folks that don't want to do it right .

No reconditioned gauges. Get new ones. Again, shop around, don't buy the first thing you see. Do your homework, summer's over, ya got all winter to do your research for next year .

If it were my vehicle, it would still be R12 .

 
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09-21-03, 07:51 PM   #14  
samwise
joe>>It scares me that you don't use manuals to guide you!

What are you talking about, read the post.

 
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09-21-03, 11:11 PM   #15  
Hey samwise...when the compressor slows down, does the belt squeal? If so, the compressor is locking up. If not, the clutch may be slipping. If the clutch is slipping, it will be VERY hot to the touch and there should be metal dust around the area. It may also melt the front seal out of the compressor if it gets hot enough. If the compressor is locking down, it may be bad, or it could also be a line restriction causing excessive head pressure. Most of the time a pressure switch will detect this, but not always, and if the pressure gets too high, the popoff valve will blow.

Is the suction line cold?
Pressure line hot?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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09-22-03, 05:20 AM   #16  
IF THE CLUTCH IS SLIPPING, IT COULD ALSO BE THAT THE MAGNET IS NOT RECEIVING SUFFICIENT AVAILABLE CURRENT.
DISCONNECT THE TWO WIRE CONNECTOR AT THE CLUTCH, AND WITH TWO FUSED JUMPER WIRES CONNECT ONE TO A GROUND AND THE OTHER TO THE BATTERY POSITIVE. DOESN'T MATTER WHICH TERMINAL, BUT U WILL BE SUPPLYING YOUR OWN POWER AND GROUND TO THE CLUTCH. SEE IF THE CLUTCH STILL SLIPS. IF IT DOESN'T, THERE IS A CONNECTION PROBLEM SOMEPLACE. IF IT STILL SLIPS, THE PRESSURE PLATE IS PROBABLY FAILED. DOUBTFULL THE COMPRESSOR ITSELF IS SEIZING. THE WINDINGS IN THE MAGNET COULD ALSO BE FAILING I SUPPOSE.

 
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09-22-03, 06:59 AM   #17  
Joe_F
Sam:

A GM shop manual is a MUST, not a "nice to have" for this repair.

You MUST always consult a service manual FIRST when doing this type of repair. Always consult something like that in ADDITION to the help you get on this forum!

 
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