AC compressor noisy - need help for AC gurus

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car is a '99 maxima. the AC compressor makes a howling/screeching noise when the clutch is NOT engaged. when AC is turned on (clutch engaged) the noise goes away.

so is the clutch going bad? or a bearing? if the clutch, can I replace just the clutch or do I have to replace the entire compressor?

anyone have experience with this?
 
so if the noise is only present when the AC is off, what does that mean? is it the clutch not fully disengaging (e.g. corroded & slipping)? I'm thinking if it were a bearing, or an internal compressor failure, I'd hear the noise all the time, or only when the AC is on.
 
You may have a broken clutch spring finger, or weak springs. The faces [surfaces] of the clutch may be rusted. The bearing may indeed be bad.
If you spray WD40 into the face area, and the noise goes away, you will narrow down the problem.
 
so the WD40 would lubricate the clutch surfaces, and if the noise subsides I can conclude it is the clutch plate (not the bearing) causing the noise - correct?

now would the WD40 cause the clutch to slip when engaged? so I would have to clean or replace the clutch plate, right? (the WD40 alone will not fix the problem)?

about the bearing -- so if I understand this, the bearing sits between the pulley and the shaft, so when the clutch is off the bearing is spinning (pulley spins but shaft is not), but when the clutch is on, the pulley and shaft are both spinning so the bearing is, in effect, stationary (e.g its races are rotating in sync). does that make sense? or is the inner bearing race pressed onto the compressor case with the shaft running through it?
 
Just like not to get any kinds of lubricants onto your braking system friction materials (pads/shoes),you shouldn't spray anything foreign onto any friction material surface such as belts, A/C clutch friction plate, etc. That would cause you major further down the road.

When in serious doubt, consider getting a proper service manual and look into the A/C clutch engaging portion and/or the bearing pack associated to the clutch disc to see if that's the cause.

Sorry to tell you that when it comes to noise coming from A/C compressor, it's not something that you can spray something and miracle happens (or hopes the noise to go away)

Also, never under-estimate the possibility of a bad/worn/improperly tightened A/C belt or belt rubber materials.
 
BTW: never under-estimate the potential damage caused by WD40....

All I can tell you is that back in my young and "naive" days, I have done enough damage by carelessly spraying with all kinds of sprays, inc. WDee40.
 
does anyone know where I can buy a clutch kit (clutch and pulley w/ bearing)? I've heard you can get them for about $70 but i can't find anyone that sells them.
 
Sorry sky,

even if you are able to get the clutch pack, chances are, you cannot service it for it would require some custom puller and tools to uninstall/install the clutch packs on typical automobile compressor.

Try searching for four-seasons (one of the largest aftermarket/OE auto refridgeration company in NA, which carries a lot of remain compressors)

Good luck!
 
Not sure about Maxima compressor, but most of the Japanese compressors allow clutch removal by relasing a 10mm nut on shaft end, pulling clutch plate (couple of screwdrivers to pry carefully). releasing snap ring to release clutch/coil assy from compressor.

Depending on location of compressor, this may/may not be do-able in place. It will have to be up high and proud to allow in-place work.

If you have to open the system, be sure to plug all open ends to avoid moisture ruining your reciever/drier. A rubber band secured plastic bag or tightly stuffed paper towel will do.

I've found used AC parts to be a great bargain. Check car-part.com for local parts for your car. I suspect you can buy the whole compressor cheaper than a new replacement clutch assy. Either replace entire compressor or swap new clutch assy to your compressor.

I avoid rebuilds from 4-seasons and their huge array of sister companies; factory aire, et al. They are bad news for quality. Too many "infant deaths" and re-do's of your hard repair work.

good luck
 
UPDATE:

I pulled the clutch/pulley off the compressor. it is definitely a bad bearing. here's some audio/video clips...
http://media.putfile.com/AC-compr-pulley-spin
http://media.putfile.com/AC-Pulley-and-Bearing-

as you can see from the 2nd clip, the bearing is pressed into the pulley. I can order a new bearing from Murray's for $30. trick is how to press it out, and the new one in. If I can't do it myself I'll have to go to a machine shop, but how do you find a competent machine shop? there's a rebuilder in Florida that will send me a rebuilt clutch/pulley/bearing for $80 as a last resort.
 
sky-

You are correct indeed (that it's the bearing).

I just couldn't believe my eyes (based on my experience so far) that the bearing can go in such dramatic ways (it wasn't like that before you said, remember?). Oh well, lesson to be learned for me (can't stop learning in this day and age).

In order to service your pulley bearing, you will have to find a 10t press and suitable adaptor plate before you can press it out and then press on a new one.

Check around to see if there's any machine shops willing to do that for you (make sure they press the bearings out and in and not use a slide hammer or ordinary hammering method) for a reasonable charge. Otherwise, consider your second option.

Good luck and let us know how it turns out?

Q.
 
Why wouldnt you buy another compressor instead of trying to change just the bearing??
 
Quote:


Why wouldnt you buy another compressor instead of trying to change just the bearing??




Because you shouldn't fix something that isn't broken. The bearing is a factory packed item that has a finite life. The compressor is lubed by the refrigerant oil. If the refrigerant charge is maintained and there is no air or non-condensables (like water) in the system compressors can last for many years.
 
Quote:


Why wouldnt you buy another compressor instead of trying to change just the bearing??




new bearing: $30 (no need to open the system)

remanufactured compressor: $250+
new drier: $45 (req'd anytime system is opened)
evac/rechrg: ~$200 (req'd anytime system is opened)
risk that the shop will screw up the evac/rechrg (too much/not enough PAG, wrong PAG type, too much R134, etc) thereby trashing the new compressor: priceless
 
Quote:


UPDATE:

I pulled the clutch/pulley off the compressor. it is definitely a bad bearing. here's some audio/video clips...
http://media.putfile.com/AC-compr-pulley-spin
http://media.putfile.com/AC-Pulley-and-Bearing-

as you can see from the 2nd clip, the bearing is pressed into the pulley. I can order a new bearing from Murray's for $30. trick is how to press it out, and the new one in. If I can't do it myself I'll have to go to a machine shop, but how do you find a competent machine shop? there's a rebuilder in Florida that will send me a rebuilt clutch/pulley/bearing for $80 as a last resort.




You may be able to hammer out the worn bearing using care not to damage the pulley. Heating the assembly first then putting ice on the bearing to chill and shrink it may facilitate removal. As for the new bearing, you may be able to chill (in the freezer) the new bearing and heat the housing (about 180 F. in the oven) and press the new bearing into place without the services of a machine shop.

If you do resort to a machine shop, there are plenty of them around in Chicago. You might try a motorcycle shop or a small engine repair shop. They often have small presses for pressing bushings and other similar duties.
 
Quote:


You can also buy a used compressor for $



you might have missed the post above. I've already removed the clutch/pulley while leaving the compressor on the vehicle.

the bearing is $30, and the cheapest junkyard compressor I've found is $115 - so that doesn't make sense.

but aside from the cost, why would I trust a junk yard part with unknown history to last more than a month? my compressor was fine until the bearing suddenly failed. better to replace with new parts IMO.
 
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