a/c compressor clutch slipping

cubanfisher · Post by **cubanfisher** » Mon Mar 30, 2009 9:41 am

Hey my a/c compressors clutch slips when i accelerate quickly to 2 or 3k rpms. i know it works with magnetism, and i was wondering if theres a way to get the clutch surface closer to the pulley to help the slipping? or any other ideas would help.

cubanfisher · Post by **cubanfisher** » Wed Apr 15, 2009 4:34 am

nobody with ideas?

F9K9 · Post by **F9K9** » Wed Apr 15, 2009 4:59 am

Are you positive it isn't the belt?

1337vending · Post by **1337vending** » Wed Apr 15, 2009 1:28 pm

The computer will disengage the A/C above 99% throttle OR above 4500rpm. After a few seconds of being below both of those values, it should re-engage.

Are you hearing any squealing/screeching?

cubanfisher · Post by **cubanfisher** » Wed Apr 15, 2009 5:47 pm

positive its not the belt. and it does it at 2500 rpms most of the time. u can see the actual clutch slowing down from the pulley. it sounds like it disengaged but trying to ingage again. my 93 ford probe gt's compressor used to do the same noise. it wouldnt engage and i used to tap on it and then u hear grabbing but letting go. when driving it sounds like a "zizzing" noise. when u pop the hood its loud

fallvitals · Post by **fallvitals** » Fri Aug 07, 2009 5:47 pm

Deleted my other posts too.

The one question I really need answered before I go further.

How can I tell if the A/C Compressor clutch is my problem, and not the Compressor locking up?

From all my researching via google. It seems like a A/C Compressor is bad, it wont function at all, wont turn, it will cause the belt to smoke, fire, all kinds of very obvious things.

My dad is curious if possibly its the compressor locking up when this is happening and causing the clutch to slip? every thing I see says the compressor is good, but I dont see anything set in stone, or any good list of symptoms.

Again, my issue is like the OP, its fine at normal rpms, only does it when AC is on, when the rpms go up, it whines.

I found this write up, he says GM models are similer, and the parts look similer to ones I have seen on rockauto, seems like the job would be similer to this

http://www.bernardembden.com/xjs/comclutch/index.htm

Looks pretty easy with the right tools.

fallvitals · Post by **fallvitals** » Sat Aug 08, 2009 12:22 pm

just bought a haynes manual. And of course it doesn't talk about replacing the compressor clutch, just the compressor.

F9K9 · Post by **F9K9** » Sat Aug 08, 2009 12:29 pm

fallvitals wrote:just bought a haynes manual. And of course it doesn't talk about replacing the compressor clutch, just the compressor.

About the only things that haynes and chilton is good for is a drink coaster or to level out a wobbly table. Have you tried a google search for something like "how to replace an automotive AC compressor clutch"?

F9K9 · Post by **F9K9** » Sat Aug 08, 2009 12:37 pm

We need to determine which units we have.

Clutch Rotor and/or Bearing Removal V7 - Direct Mount

Compressor Clutch Plate and Hub Assembly Removal HT6/HD6/HU6

Post by **HenryJ** » Sat Aug 08, 2009 12:46 pm

If the clutch is indeed slipping there will be a debris field. There will be what looks like brake dust and metal dust around the clutch face surfaces. Large amounts of this stuff. A little bit is normal.
Not a common failure point but I have seen it a couple times. If you are to the point that you see oily deposits around the AC compressor clutch you are likely too far gone to replace the clutch alone. The compressor seals tend to get cooked from the heat of the slipping clutch or over heating clutch coil. Replacement of the complete compressor is a better choice then. Plan on about $300 for parts using a rebuilt compressor as you will need a new orifice tube and dehydrator too.

You can replace just the clutch. It is a PITA. They tend to seize on the shaft and come off very hard. It can be done, but be prepared if things go bad.

The air gap is adjustable. That does not usually make a difference in holding power. It just keeps you from over extending the springs when it engages. If you have too wide a gap it can break the springs. Too little gap and it rubs making noise when free.
The coil determines the holding power. A weak coil could allow slipping. Oil on the surfaces could also cause slipping. Cleaning the clutch with some electrical cleaner might be worth a try in that case, although the oil is a sign that replacement will be needed soon.

I would clean the clutch out first. Compressed air and maybe a little electrical cleaner. Then I would look for a weak or worn belt tensioner and think about investing in a new Gatorback belt. Belt slipping is more common.

fallvitals · Post by **fallvitals** » Sat Aug 08, 2009 11:08 pm

f9k9 wrote:
fallvitals wrote:just bought a haynes manual. And of course it doesn't talk about replacing the compressor clutch, just the compressor.
About the only things that haynes and chilton is good for is a drink coaster or to level out a wobbly table. Have you tried a google search for something like "how to replace an automotive AC compressor clutch"?

Looking through the Haynes I just got, its pretty simple info, but still lots of stuff I didn't know. And yeah, I did google the subject, if you read above I posted a link to a clutch removal tutorial on a clutch thats similer to the GM ones.

"Clutch Rotor and/or Bearing Removal V7 - Direct Mount

Quote:
Compressor Clutch Plate and Hub Assembly Removal HT6/HD6/HU6 "

Where did those come from? Sounds like some sort of repair manual, but im at a lose here?

I will have to look tommorow, but I dont recall seeing any oil at all, or any large collections of dust. Heres a picture I took the other day with my phone:

http://photos.imageevent.com/rc_racer_0 ... C04134.JPG

I have started to turn the AC off when I know im gonna be on the gas hard to prevent slipping. I see on ebay there are complete compressor kits, with oil, dehydrater and other junk for around $200 if I recall correctly. (Heres one for $172 shipped, 1 year warranty, http://cgi.ebay.com/ebaymotors/New-AC-C ... ccessories )

I wish it was the belt slipping, but I guarentee its not. Ill do the compressed air, and electrical cleaner spray and see if it makes a differance. The compressor seems to be in good shape.... I would just hate to dissaemble a perfectly good AC system for the clutch.

In that tutorial I found above, the parts he took apart looks very similer to the ones on rock auto. I think he said it is a GM compressor as well. He used a gear puller to get the pully off, and a special AC compressor clutch removal and installer tool. I figure advance has both tool sets available to loan. With those,, It doesnt seem like it would be too tough of a job? Seems like it would be similer to the pinion seal I recently did.

Im gonna do some more researching, and look for the oil and other things you suggested Brule. I guess best case scenario is I get a used comrpessor from ebay, strip the clutch from it and replace my worn one... worst, the whole shabang.

edit- I think id rather change the whole compressor/drier/etc, but stil thats a lot of money... vs picking up a $65 used compressor and stripping it for the clutch.... any one know how much would it be to have a ac shop drain the system, let me part swap, then flush/charge/whatever they do?

Post by **HenryJ** » Sun Aug 09, 2009 6:34 am

Test the coil, measure the air gap and then decide. If your compressor is good, then pull your clutch. You have nothing to lose there. If you are successful, then replace it with a new clutch. Don't take chances on a used one. JMO.

Equal to or slightly more than the price of parts for labor to pull the system down and charge it back.

fallvitals · Post by **fallvitals** » Sun Aug 09, 2009 10:37 am

If im gonna replace it with new parts, I might as well just buy that compressor kit on ebay for $170. I just figure a used part shouldn't be a big deal. It really isnt something that breaks down a lot.. but I do see what your saying....

Crap, lol. The more I look at it, the more im seeing me buying that compresor kit... Cause I do understand if its slipping theres a good chance the bearing is gone, the compressor could possibly be not far behind, and the seals as your explained...

Im not sure what you are comparing the the cost of charging the system back too? Think itll be close to $100 or more?

I also don't imagine it taking more then an hour to swap out these parts? seems like a super easy swap on the bright side (if I do the whole compressor/drier)...

Post by **HenryJ** » Sun Aug 09, 2009 2:07 pm

Charge to reclaim the refrigerant $100
Charge to refill the system $100+

You better check before you dive in that deep.

Don't forget you will need compressed air and a solvent to clean the system before you put it all back together. Chances are your old system used PAG and this kit has Ester. Ester to a PAG system is Ok, Pag to Ester is not.

border man · Post by **border man** » Sun Aug 09, 2009 2:51 pm

fallvitals wrote:It really isnt something that breaks down a lot..

I'm on my third A/C system

The last one cost me $1300 hundred dollars for AC/Delco parts and labor

Post by **HenryJ** » Sun Aug 09, 2009 3:24 pm

border man wrote:I'm on my third A/C system

Yours probably gets turned down for a day or so in late December, right?

You probably use yours more than double the hours than mine will ever see.

border man · Post by **border man** » Sun Aug 09, 2009 3:33 pm

It got turned off for a whole week 3 years ago when I drove to Seattle/Vancouver BC in December

Post by **HenryJ** » Sun Aug 09, 2009 4:15 pm

border man wrote:It got turned off for a whole week 3 years ago when I drove to Seattle/Vancouver BC in December

fallvitals · Post by **fallvitals** » Sun Aug 09, 2009 6:56 pm

wow, that sucks. That still seems like an excessive ammount on break down on one item reguardless of where your from?

I sprayed the clutch out with the air compressor today, good ammount of dust came out. Started to spray it with the elctric cleaner, but it didn't have the nozzle for it... and i forgot, but the air compressor didn't help none.

Ill have to find a good AC shop... no way am I gonna pay the dealership twice what a normal shop would to drain it, let me part swap, then flush/charge/leak test.Im gonna call around to some shops tommorow to see what that is gonna cost... im fearing just as much as the whole new compressor kit ($172) ?

fallvitals · Post by **fallvitals** » Sat Aug 22, 2009 2:06 am

Let me know if I am making a mistake here...

Im thinking of just leaving the AC compressor clutch as is. The AC is working fine. Since I blew the clutch out with the air compresor (I have forgotten to spray in the electrical part cleaner, need to do that today). I can no longer hear the squeel while driving, but its still there. So... I am thinking maybe geting some dust out helped it some.

Anyways, Im thinking about just leaving it be till something finally screws up and needs replaced. I am not gonna pay for new clutch parts, I can get a whole compressor kit for that same ammount, if not less. And I dont want to replace the compressor/drain and fill ac system for the clutch.

I figure ill just put the money away for the parts, and just leave it be till something finally goes. And with the money close by, ill have it fixed shortly anyways.....

Sound like just a dumb redneck idea? Or make sense?

Post by **HenryJ** » Sat Aug 22, 2009 5:22 am

If it ain't broke...

DLP · Post by **DLP** » Sat Aug 22, 2009 8:33 am

Fix it till it is

fallvitals · Post by **fallvitals** » Sat Aug 22, 2009 11:26 am

lol, the clutch is infact on its way to being break, slipping at higher at higher rpm... I just dont see any point in it right now putting so much time in effeort in something thats making a loud squeel, that apperantly is quieter now, only when on the gas a little hard. So theres my answer, lol, thanks guys

F9K9 · Post by **F9K9** » Sat Aug 22, 2009 6:14 pm

Summer is winding down. Start shopping used compressors now. I did research the clutch replacement and it is pretty extensive and requires special tools or what Brule may have handy at work.

Keep it high on your list of priorities. Don't be like me and forget about a roof leak until it leaks during a rain storm.

My excuse last time was that it is "to cold to patch it now honey". Four months later while the drywall has a large soft bubble in it, she "reminds" of the problem.

fallvitals · Post by **fallvitals** » Sat Aug 22, 2009 9:41 pm

lol. I really dont use my ac too much... justo nlonger high speed trips really, most of the time.. even though its been in the 90s all week, iv had the windows down pretty much every day, lol.

im gonna set aside the cash. I mean, its jsut the clutch screamin'.... might last forever while screaming at high rpms, apperantly the air compressor trick quieted it down some. So.. ill keep the cash aside till its time. Wouldnt take any time to change it out. The longest part would be having the AC shop do their part... (replacing compressor/drier/etc)

Pretty funny story though, lol. Especially the drywall part

F9K9 · Post by **F9K9** » Sat Aug 22, 2009 10:30 pm

fallvitals wrote:l..........Pretty funny story though, lol. Especially the drywall part

I really do not make this stuff up for laughs. It really is my life!

I have no excuse for not fixing it today.

Gonna be sunny and in the 70s. I have to hit the roof and the grass today. Problem is I have two sweet adjustable upper control arms for the heep needing installed. I think I'll be wheeling a mower and chalk gun instead.

fallvitals · Post by **fallvitals** » Sat Aug 22, 2009 10:38 pm

lol, it never ends eh?

Your bad luck wouldn't be so funny if I didn't pretty much follow right behind you in your trail of misfortune

My day should be better, if I have time to do things I want, (I got all my grass done) i will shoot my bow some, then start on building another dozen uncut arrows myself that I have had laying around since last year. I now do all that work myself, a lot more fun, and heck of a lot cheaper then having some archery shop "pro" do it!

F9K9 · Post by **F9K9** » Sat Aug 22, 2009 11:31 pm

It really all evens out though. Had a decent trail ride today until one of our newer members broke. Than it took all of us to get his rig out and back to a trailer. A close knit club is worth the investment of time and dues. All the rigs are street legal but, those fortunate enough to have the money for tow rigs and trailers will get you back home even if, it is a hundred miles out of their way

T Man · Post by **T Man** » Sun Aug 23, 2009 1:49 pm

Didnt see it posted, but try replacing the compressor clutch relay. Over time the contacts deteriorate and the compressor clutch will lose voltage causing them to slip. Big problem with older ford clutches

JaVeRo · Post by **JaVeRo** » Fri Sep 11, 2009 8:07 pm

Probably a little late but here is my story.

I just recently replaced the compressor clutch on my wife's Blazer. It would engage fine but it had problems disengaging. I had replaced the pulley bearing on the '01 crewcab a couple of years ago and knew the clutch faceplate was spring loaded to force it away from the pulley and disengage.

The '03 Blazer had a different design for the clutch, it was just a rubber bushing that pushed it out. The rubber got weak and was letting the clutch drag on the pulley after disengaging. The new clutch I put on was a better design.

The tools to remove and replace the clutch was $30 at napa. I had bought a cheaper one (performance tools) a couple of years ago with the interchangable tip and it broke this time. With the right tool it's not that hard to do.

I chose to replace the clutch instead of replacing the compressor just so I didn't have to get someone to vacuum and refill the system.

I can take a picture of the clutch I took off if it will help anyone.

James