: Air conditioning compressor clutch bearing



kjhansen
10-17-09, 07:23 PM
I have a 1995 SLS and it's been a very reliable car until it hit 190,000 miles. Everything seems to be going at once. Tensioners (both), idler pulley, alternator, a single coil pack and now a new noise from the driver's side of the engine. I've narrowed down where it's coming from and I believe I know what it is because I've had this noise before on a different car. The noise is a squeal and then a grinding kind of noise and it can't be the alternator (new), the tensioner (new) or the idler pulley (also new). I can't hear it coming from the power steering pump either (I have an automotive stethoscope). PLUS the noise goes away if you turn on the A/C (the A/C still works well). So I'm pretty sure it's the A/C compressor's clutch bearing. When the pulley free-wheels it makes the noise. When the compressor is engaged and takes up the load, the noise goes away.
Now, in the past you could replace the clutch bearing without removing the compressor from the engine. This requires special tools (which I don't have), but it could be done--if you could get to the front of the compressor, which was not a problem with RWD cars... . Can it still be done? Is there enough room if you remove the right front tire? Can you even buy the bearing separately?
So far I've done all the work on this car myself, and I'd like to keep doing that. I'm willing to buy the tools, but I need to know if it's reasonably do-able.
BTW, the alternator was a pain, but not because it was hard to get out. With the plate below it removed and the passenger-side fan pulled out, it dropped right out. It was a pain because it is held in by FIVE (5) bolts, not three like noted in a previous thread.
Keith

Ranger
10-17-09, 07:39 PM
I just did it on my wifes '96 Bonneville (3800). You should be able to do it through the wheel well. Might have to remove an access panel.

kjhansen
10-17-09, 10:05 PM
Thanks. Where did you get the tool and the bearing?
Keith

Ranger
10-18-09, 12:31 PM
I got the tools from AutoZone (rental program), BUT they gave me the wrong ones so I had to go back and still did not have all the right ones. You need several. Also got the bearing there, but was never able to get to the bearing. I got the clutch off and realized that the noise was from the clutch rubbing and the bearing felt good, so I put it back together and gaped the clutch and all was well. A FSM would be a big help unless you have done this before (I hadn't). The bearing is peened in place so you have to grind off the peens and repeen the new one.

kjhansen
10-18-09, 03:56 PM
Thanks.
Keith

tateos
10-19-09, 12:28 PM
Or...you could put a new compressor in... and save yourself some trouble. At the least, evacuate the system and remove the orifice tube and check for trash thrown off by the compressor, and then decide what to do.

kjhansen
10-19-09, 04:33 PM
I think that maybe a new compressor might be better in the long run. How do you evacuate the system and check the orifice valve? How hard is it to remove the compressor? Gotta be fewer bolts than the alternator? Right? Right?
Keith

Submariner409
10-19-09, 05:41 PM
"Evacuate the system" means to use an air conditioning rated oil-free vacuum pump to pull an almost absolute vacuum in the system, purge it with refrigerant and refill the system with the proper charge, all done after making necessary repairs. Not an everyday in-your-garage procedure.

Ranger
10-19-09, 06:12 PM
To properly evacuate the system you need to recover the refrigerant. Then you open up the line by the orifice tube and remove it for inspection.

tateos
10-19-09, 06:48 PM
I think that maybe a new compressor might be better in the long run. How do you evacuate the system and check the orifice valve? How hard is it to remove the compressor? Gotta be fewer bolts than the alternator? Right? Right?
Keith

Evacuate the system CAN mean loosen a fitting, or attach gauges and crack a valve, and let the refrigerant gradually leak out - gradually so it won't carry all of the oil with it.

Yeah...I have done both and I think the AC compressor could actually be fewer bolts. Pretty sure there is just 1 bolt that attaches the AC "manifold" onto the back of the compressor; the manifold is how the high and low side refrigerant lines are connected. Then a couple bolts in the front, and 1-2 in the back.

The orifice tube is in the refrigerant line, in the firewall area. Before you take things apart, run the AC and feel that line - the orifice tube is where the line goes from hot to cold. There will be a fitting to loosen there - then you can pull out the orifice tube - a partly plastic thingy. The screen that is part of the orifice tube catches all the larger debris circulating in your AC system and is a pretty good indicator of the health of your AC compressor.

When you're done, you will need to evacuate the system just like Sub described, and replace any lost oil and, of course, the refrigerant. You could hire someone to do it for you, or get the vacuum pump and gauges and do it yourself and pay for the tools with the money you saved by doing it yourself. For example, here are what Harbor Freight offers:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96677

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=98076

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66466

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92649

kjhansen
10-19-09, 06:49 PM
I know a guy who will vacuum and recharge the system. But how hard is it to remove the compressor? When I pulled the right front tire and removed the plastic protective pieces, I saw two bolt heads, but couldn't see how to get the lines off the compressor so I could pull it out. Are they flexible and long enough that you pull the compressor out part way to disconnect them?
Hmmm. Maybe I should stick with the clutch bearing...

Ranger
10-19-09, 08:04 PM
Forget this one. It will never do the job.

http://www.harborfreight.com/cpi/cta...emnumber=96677

kjhansen
10-20-09, 11:17 AM
Well, I jacked the car up and crawled under. I can't actually see everything on the back of the compressor as it is right up against the oil filter and oil filter attachment that bolts on the side of the block. Frankly it looks like a real pain to get it out. It obviously doesn't pull out once the two bolts are undone in the wheel well, as I can see one bolt in the back that is firmly attached to the block. Anybody have any pictures of how this is done--and what the orifice tube looks like?
Keith

Ranger
10-20-09, 03:54 PM
Here is an orifice tube. They come in different colors. Color defines orifice size. You can't see it though, It is inside the A/C line at the coupler along the firewall on the passengers side.
http://www.autoacsystems.com/_store/storepics/A5101.jpg

kjhansen
10-22-09, 07:51 AM
I ended up replacing the A/C compressor, the accumulator, and the orifice tube. No warranty on the compressor unless the other two were also replaced. Good thing though, there were little bits of metal in the system, so they would have messed up the new compressor. All the funny noises under the hood are gone and the car acts like a Cadillac once again.

Ranger
10-22-09, 10:59 AM
I ended up replacing the A/C compressor, the accumulator, and the orifice tube. No warranty on the compressor unless the other two were also replaced. Good thing though, there were little bits of metal in the system, so they would have messed up the new compressor. All the funny noises under the hood are gone and the car acts like a Cadillac once again.
In that case you should have replaced the condenser as well and flushed all the lines.

tateos
10-22-09, 01:35 PM
Ranger is correct - that's exactly what I was told had to be done to ensure the best and most durable results. Maybe you should look into having the system evacuated again and pull the orifice tube and see if it has caught any more trash; or ideally, you should evacuate and flush the system, replace the condenser, and also install another new accumulator. I was told that the reason to replace the condenser is that the tubes are so small you can never be sure they are all clear after flushing.

Ranger
10-22-09, 02:41 PM
I believe the reason for changing the condenser is that they are no longer serpentine, which would ensure a good flush. They are now a ladder type so they are almost impossible to guarantee a good flush.

tateos
10-23-09, 03:05 PM
I believe the reason for changing the condenser is that they are no longer serpentine, which would ensure a good flush. They are now a ladder type so they are almost impossible to guarantee a good flush.

I think you're right, based on what I have read about the design, but that wasn't was I was told - I was told it is because the tubes are so small. But again, I think you're right - the design is the real reason.