A/C compressor help.

[yippeekyaa]

A/C system doesnt work. Took car to shop and was told bad clutch. Quoted $750.00 for fix. Did the old second opinion shuffle and left. Some browsing on the web and im seeing new compressors in the $300 to 400 range. Estimate i got says $600 just for the unit. Found a few clutch kits for $150. So my question is should i go for a new compressor or just replace the clutch. Is the clutch an DIY item with the loaner tools available at autozone/advance auto? By loaner tools i mean the clutch puller tool. I can easily change the compressor itself but it doubles the cost. Only thing i can see paying for at a shop is the capture of the coolant fluids and replacment of them once the compressor is changed. And btw i found this compressor for 1.25 yup a buck and a quarter. http://catalog.autopartsgiant....giant Obviously a typo. If the clutch is not an option im leaning towards an ac delco unit new for 299.any advice appreciated thanks.

[kevera]

If you think you can do it,I would replaced the clutch myself.Save the money for some beer and wings.

[yippeekyaa]

I would rather just replace the clutch. No fiddling with coolant recovery issues. But I was hoping for verification that it is indeed replacable. thanks.

[kevera]

I wish I could help you there,haven't had to replaced it on the Vibe yet.It is a GM compressor,as with most they are replaceable.

[joatmon]

this may apply, it's for a matrix, I don't know if it's a toy or GM part, or if they are the same between matrix and vibe, or what year vibe you have, in fact there is a lot I don't know

Attached files x040001.pdf (153 KB) 

[yippeekyaa]

Its a 2003 GT. And thank you very much for that pdf. Printed and reading it over now. On one hand just doing the clutch will be cheaper, but more work. ohhhhhh decisions.

[joatmon]

I looked in my car, the location of that will make it a pain to work on, maybe you can unbolt it and move it around somewhere, maybe come up from the bottom. but for $150 instead of $750, well, that would be worth a some amount of pain.I would first make very sure that the electrical circuits driving that clutch were 100%. Don't know how much testing the shop did to determine that it was the clutch and not some other electrical part somewhere (like a fuse, or a relay) but you'd hate to suffer through the clutch replacement only to find out it wasn't needed

[Raven]

There's tons of them on Ebay from $40.00 and up with around 48K. Are you sure the compressor is even working? Does the compressor cycle on when the A/C or defrost is on? If the compressor does not cycle on either the system is low on freon, the compressor is done or some other problem exists. My experience with A/C clutches is that when they go they usually seize and burn the belt. They don't usually fail and start slipping.

[yippeekyaa]

The compressor itself is fine. The diagnostics the shop did on it included a full vacum pull down of coolant and recharge to spec. It had the correct lvls in it as the pull down showed the amount removed. They also hooked a computer to it and analyzed the signals sent to the compressor. there is also voltage being sent to the compressor verified with a test light. The clutch never engages and you can reach down with the engine off and turn the compressor by hand. It is very free. I did the same on another vehicle for comparison and could barely turn it. Its certain at this point that it is simply a bad clutch.

[eyedoc]

I am having a similar problem with my 2004 Pontiac Vibe (front wheel drive, not GT, 1.8L engine). The A/C stopped working. My wife took it to a repair shop, was told something electrical was wrong, that the system was properly charged with R134a, and that it would be $1200 to fix it.When pressing the AC button while idling, the engine increases RPM. The clutch on the compressor does not engage. The wire leading to the snap connector on the compressor goes from 2-3 volts to 13 when pressing the AC button. The wire will supply over 4 amps of current to a 50 watt 12 volt halogen bulb. The bulb goes on and off properly as the AC button is pressed. I removed the serpentine belt. I was able to remove the front plate off the clutch, and the snap ring, but the pulley has a press fit bearing that I could not free from the housing to inspect the coil. The lead going to the coil has infinite resistance. The clutch plates are scratched lightly and worn, but are not discolored from heat. The compressor shaft turns freely with no resistance and no play. I was able to unbolt the compressor from below, and angle the clutch to provide enough room for a gear puller. I just bought a 4 and 8 inch 3 jaw puller to be delivered soon. A new AC Delco clutch 154851 costs $94.79 from RockAuto.com. A large socket should allow me to pull the pulley off by pushing against the aluminum compressor housing without touching the shaft. I don't know if the field coil can be removed without discharging the 134a, but I suspect it can be. My low and high side pressures are currently 70 psi.I am not sure why a field coil would fail. Could it have a thermal fuse that was heated by some other problem with the compressor? If so, I waste 100 bucks to find it out. We already have spent $60 for "air conditioning service". I will talk with the shop owner to see what his thinking was. I suspect he felt the most reliable repair would be the compressor, receiver/dryer and maybe the condenser and expansion valve too. A Denso 471-9006 is $439.50 on Amazon, AC Delco 15-20754 runs $258.23. Opening up the AC system starts at $60 for someone to evacuate it, and the price of a receiver/dryer, compressor, and I hear the condenser and expansion valve should probably be replaced too. I have a vacuum pump that will pull a 50 micron vacuum, and a cylinder of CO2 that could be used to pressure test the system (not nitrogen, unfortunately). AC repairs are generally best left to professionals. If I could find one I could trust, I could have had more fun this holiday weekend. Wife's opinion? Let's go buy a new Traverse.Anyone out there replace the AC clutch?

[eyedoc]

The AC is working again. It is not necessary to discharge the AC system to replace the clutch.To remove the clutch, first jack up the front of the car on jackstands. Remove the plastic engine cover off the bottom of the engine, and also remove most of the screws and plastic fasteners holding the plastic cover inside the passenger front wheelwell. Use a Vise grip pliers and a cloth to clamp the AC clutch pulley to the magnet clutch hub. This will prevent the clutch hub from turning while you loosen the torx screw holding the hub in place. I used a small torx bit held in a vise grip pliers given the tight clearance. Once loose, now remove the serpentine belt from the pulley. There are 3 bolts (12 mm) holding the compressor to the engine block. Two are removed with a standard socket wrench from below, but the top one requires a long extension and universal joint to reach it from above. Once these are out the compressor can be lowered a bit. I fastened twine around the back of the compressor and tied it to a stick resting on the engine and radiator to hoist the back of the compressor up, thus angling the pulley down. The clutch hub can now be removed with more clearance. Take off the first snap ring now. You will need a long-nosed strong snap ring expander to do this. Once removed, the pulley's steel bearing was fused from corrosion to the compressor's aluminum housing. I could not pry it off. This 4 inch puller worked very nicely to pull the pulley off. A second larger snap ring holds the magnet clutch starter in place. The clutch starter has a lead that requires removal of another torx screw and a plastic fastener to free the lead from the compressor housing. Removing the plastic fastener without breaking it is a trick: use needle nose pliers to compress the fastener before pulling it out. Once removed, I found out why my coil had failed. Breaking open a square plastic box (found on the side of the coil opposite to the side the lead enters the coil) reveals a small thermal fuse (250 V 1 amp 176 C) that had blown. I used a small length of 16 gauge solid copper wire and soldered it around the fuse, bypassing it. Now the coil had 4 ohms of resistance again, and when the lead was connected to the positive battery terminal, it hummed and generated a strong magnetic field. I covered my fuse repair with clear silicone caulk to prevent a short. I cleaned the compressor housing with wet/dry sandpaper to remove the corrosion, as well as the inside of the pulley bearing. Replace the magnet clutch starter and snap ring. With a light coat of WD40, the pulley bearing slides easily back on. Replace the second snap ring. Screw the clutch hub back on. I left out one of the two washers (each were 0.012" thick) assuming wear of the clutch faces had occurred. Once the clutch hub was tightened back on, I measured a 0.017" gap between the pulley and hub using a feeler gauge. Standard clearance is 0.013 to 0.023". This would suggest that the clutch faces had worn, the gap opened up to 0.029", the clutch started slipping, and the friction heated the thermal fuse in the coil until it melted. After bolting the compressor back in place and replacing the serpentine belt and plastic panels, and hooking up the lead, the clutch now works fine with no slippage. The compressor heats up to 140 degrees F during use, but the pulley only goes to 130 degrees F.The only uncommon tools required are a good snap ring expander, feeler gauge set and a 4 inch gear puller. The total cost of the repair for me was the 12 dollar gear puller. I still need to replace the clutch as soon as I can find one in stock, since I bypassed an important safety feature on the pulley. That's $1087 saved.

[northvibe]

oh sweet write up.Thanks for posting your issue and a solution this will for sure help users in the future!

[eyedoc]

Thanks to the board for providing the service manual!I forgot to mention that a section of steel tubing (mine was 1 5/16" OD, 1 3/16" ID) 1 1/2 inches long capped with a piece of 3/16" steel flat stock is necessary between the gear puller and the compressor housing. I got the idea from here, where a socket taped to a washer is used. You have to push against the compressor housing, not the shaft, to pull the pulley.

[fss106]

I just emailed eyedoc's write up to like 15 different people who have been struggling with this. Awesome! One question.... how long did it take?

[eyedoc]

6 hours. I spent time making the steel spacer, and had to modify my ring expanders to work properly.

[Giant Mosquito]

Thanks for the writeup eyedoc. It helped answer a lot of questions my brother and I had while replacing the AC clutch today.A word of warning: the less experienced person (like my brother and I) might take closer to ten hours than six. Also, getting those snap rings back on is a real cussing job.

[fss106]

i ended up finding an independent mechanic to do this repair for me for $193. (i had already bought the part) i think he was kicking himself when it was all over.

[flowdam]

I too wanted to thank you for the info. I bought a used compressor off of ebay that had the clutch intact. I got mine for $35, but most are in the neighborhood of $75. I then was able to go through the steps on the workbench to more easily see how each component would be removed. I got the replacement coil off of the unit, and I still have the rest of the compressor as a backup.The few things that I did different:> I used ramps instead of jack stands. Either one will get the vehicle up high enough to work on it.> I didn't end up needing the universal joint. I got a 3/8 ratchet down beside the cooling fan with a short socket and maybe 3" extension.Last, I've added a visual to go along with eyedoc's fine writeup, but it's larger than the 2Meg limit. So if anyone is interested email me:flowdam@yahoo.comThanks Again.PS- I may try opening the plastic box and replacing the thermal fuse on my old one to have as a spare.

[Giant Mosquito]

Yeah. We got the top compressor bolt off with just a ratchet, a long socket and a spotter to help find the darn bolt.