A/C Compressor Making NOISE

[dazed]

OK I heard a noise the other day under my hood and upon further investigation it turns out its from the A/c Compressor. The noise was happening with the A/C off (unplugged all winter and barley ever used). So I hook up the A/C (plug it back in) and engage clutch... NO MORE SOUND! OK so I at least isolated the problem. Upon further looking at front of clutch plate i see small metal fragments. I found out that i have a clutch puller (nice) and proceed to remove the nut ....NO NUT! Okay then I look at gap between clutch and pulley and really couldn't see any (like it was almost touching. So I pull the clutch off and now no more noise...Great but I think I would like to use the A/C some time this summer so I'm in the need to repair this. Upon further looking at the back of the clutch I noticed that half is shiny (were it was rubbing) and the other half dirty. Also there was a bunch of dirty dried up grease in the hub... and I Spun the a/c pulley after removal and feels good (unlike before i pulled the clutch)...no real slop either.

So what happened and how can I fix this? I don't believe the pulley had walked out since the circlip is still on it. I don't quit understand that If i reinstall the clutch and give it 20-30 thousandths of clearance and then install a nut tight (with the clutch and key ) wouldn't that pull it together thus touching?

Also is the clutch supposed to spring back somehow after power is shut off...and thats what might be happening?

Is a clutch kit with the pulley my only option?

I'm kinda afraid if i go pulling the pulley off I might either break a seal in the A/C or rune the magnet or bearing since I probably don't have the Correct Puller.
Is there a way to put the clutch on without a puller..or would tapping it in risk damaging the bearing....


Thanks For any help...sorry for the long post and many questions


Also anybody know the correct nut size and pitch...im guessing its metric...1/4 -20 looked about right but wasn't and the threads looked a little tighter than 20 pitch

 

[6.2 turbo]

On some the nut doesn't even touch the clutch,newer ones don't even have a nut,its a press fit, no doubt your clutch spring is a little weak,but if you set the gap it should work for a while.

 

[btfarm]

One thing you should know is that the compressors are set up to run occasionally to keep them internally lubricated and to keep the clutch "pucks" from rusting/getting gummed up. The way they do that is by cycling when you turn on the defrost so if you had it disconnected the cycle feature wasn't working. I'd just give it a cleaning as best you can, set the clearance and leave it connected. If it's shot, you'll know it. Otherwise you're good to go for now.

 

[Brooklyn Tow]

My A/C system was open and had to change a line....well I lost a lot of oill when the line was removed (atleast it looked like a nice stream poured out)....Question,...How much oil should i put back in to the system? Whats the capacity? What Kind (wt, etc.)?

 

[WarWagon]

My A/C system was open and had to change a line....well I lost a lot of oill when the line was removed (atleast it looked like a nice stream poured out)....Question,...How much oil should i put back in to the system? Whats the capacity? What Kind (wt, etc.)?

8 oz of oil in the system. All pickups.

2.5Lb R-12. R-134A is less.

Replace the accumulator as it will have sucked water from the air with an open system. 30 min and it is ruined... Water in the system will freeze and the ac quits for 5-10 min and then starts working again. Then corrodes over time.

Use Ester oil for R-12/conversion systems.

PAG oil for R-134A, GM will be on the container as there are several viscosity grades out there.

As to the OP - Replace the clutch. A bad clutch will slip and burn out the bearing and front compressor seal. (Slip is just dragging w/o the compressor turning when the A/C is on. Sh*t gets hot quick!) Get the proper tools to do the job now as tools are cheap. A shop can do this if the tool cost is high and you can rent the tool. Otherwise you will be changing the ruined compressor.

Worse an A/C clutch burn up can blow the bearing and you are stranded with a broken belt and bad belt drive system.

 

[bk95td]

I don't think the clutch itself wears out. Not much there to actually wear. I'd replace the bearing. It may feel ok with no belt tension but can still be bad. I've had 2 that were noisy and replaced the bearing [both had over275,000 miles]. It fixed the problem. Bearing part number: BCA/National 907257 Bore 1.5743 OD2.4411 Width .812 Neither had a nut on the shaft. The installer uses the threads to attach to the shaft. The bearing comes out the side of the pulley with the punch marks in the bore[the other side has a lip] After the new bearing was in the bore I took a center punch and made new dings in the bore to hold the bearing in.
If your old bearing spins freely it is getting low on grease.

 

[dazed]

OK, first thanks to 6.2 turbo, btfarm, WarWagon, and bk95td.:thumbsup:

Well Looks like I got everything from just put it back on, to pull the pulley and replace the bearing (Don't get me wrong, I appreciate the different input).

I drove 25 miles without the clutch on yesterday and had no problems with any noise from the a/c compressor.

Okay,the no Nut on the shaft makes sense from a clutch installation point. I would say that the pulley spins but with some drag (possibly grease is ok in bearing) but no roughness....but again that is with no side load from the belt as bk95td points out.

I did find this article that gives some how-to's http://flashoffroad.com/Maintenance/hvac/airconditioning/clutchPullyService.htm This was the best that I could find even though its for a Hummer but the engine and components should be the same or similar.

So, with everything running fine without the clutch I am kind of up in the air about the bearing, but still cant understand why i was getting the drag... I guess i have to stop and visualize how the pressed in clutch is affecting this (I mean it was fine, why now). I think my first effort (which BTW is the cheapest and easiest) is to clean it up and reinstall the clutch with a little grease in the pulley or on the clutch shaft and see what happens ( i still may put another hundred miles or so on the truck before i do this to see if the bearing is holding up. Also note the sound i heard was from the clutch dragging on the face of the pulley ...so not the bearing.

If I do need to go the route of pulling the pulley, and replacing the bearing($20)...would it be feasible to reuse the same clutch and pulley, or buy a new one with a new clutch($100)?



.

 

[bk95td]

I still say just the bearing. You don't need a special tool to get the old one out. Just a piece of pipe or shaft slightly bigger than the bore of the bearing to drive the old bearing out. It doesn't matter that it trashes the bearing from hitting it with a 3lb hammer because it is being replaced anyhow. It does drive out hard because of the dings in the outer bore to hold it in.

 

[WarWagon]

Clutches do wear out. Usually the compressor pukes before this happens. There is a gap specification for clearance to set the clutch while pulling it on. The noise you are hearing is from weak ‘kick out’ springs dragging the clutch. Possible an impact bent the clutch. (Those springs also drive the compressor.)

I had a clutch making this noise that the spacing was reset on. The first exit out of Vegas the clutch did not start the compressor and burned up. I had to cut the v belt off as the bearing came apart. I was able to replace the clutch and avoid opening the R-12 system.

I would replace the entire clutch now. If it is cheaper without the magnet go that route. It is making noise and asking for parts…

 

[dazed]

Well Yesterday I Finally got a New Clutch Assembly (with the bearings, magnet, and pulley). It came with Lifetime warranty from Napa for $116 (shop cost).
It all came off easy enough with the right Pullers (Compressor still in truck)....but kinda sucked getting new Magnet and pulley on with board and Hammer....
I should have unbolted compressor so I would have had a better (more power with hammer) angle to beat it on. Circlip was a little tight...so I ground it down a little.

I now have cold air again :thumbsup: ...Thanks for everyones help!

 

[Acesneights1]

Price out a whole new compressor. It may be worth it. On my dually a new clutch was 150$. A whole NEW compressor with clutch was 183$. Not much grey area there on what to do.

 

[dazed]

Price out a whole new compressor. It may be worth it. On my dually a new clutch was 150$. A whole NEW compressor with clutch was 183$. Not much grey area there on what to do.

Except my system was still in working order from factory...had never been tampered with....Would cost more to vacuum system and recharge.

 

[davo727]

Good that you got a lifetime warrantee on the clutch,

My experience with murray and 4 seasons clutches for r4 compressors has been that they are made out of very soft steel and with the heavy use they get here- Houston , they only last about 25,000 miles compared to the oem which lasts 120-150K miles.

 

[Acesneights1]

Except my system was still in working order from factory...had never been tampered with....Would cost more to vacuum system and recharge.

Yeah and think how you'll feel after spending that much on the clutch and then the compressor craps out a month later due to age. I do my own vac and charge so I don't have issues with that.

 

[davo727]

Yep, A vacuum pump and a gauge set should be in everybodys tool kit

 

[Acesneights1]

Vac pump s a bit pricey(A good one anyway) but guages are cheap. My Robinair guages are over 30 yrs old and still work fine. Been through some hoses. They were my Fathers. I finally canned his morphadite Robinair vac pump(Thing was tremendous and took forever) and got a smaller Robinair and it was around 2-300$ IIRC.

 

[Burning oil]

I just bought a vac pump from Harbor freight for $69 when I did my system recently.
If your going to open the system I highly recomend a VOV type orfice tube. Makes a huge difference in how quickly it starts blowing cold and idle air temps seem colder. Kenny or War Wagon turned me onto them. This could be the coldest a/c system Ive had.
The new compressor was $136

 

[Acesneights1]

It was Warwagon. I had never heard of them until he posted it. Only thing I have seen is guys using Ford ones. I have personally never used anything but factory on customers trucks. Didn't really work on many GMs anyway. I mostly worked on Peterbilts, Macks Cat HE etc. No money on car a/c work. People are cheap. Oh..what's it going to cost ?? Oh that much ?? You get a guy in a dump truck or Payloader working in gruelling dusty heat all summer they don't even ask, just fix it. Plus being that I was mobile and came to them after hours so's not to have to lay a truck or machine up...It made me alot of money.