OT - Another call for GMC experts AC Comp Clutch

You guys have saved me so much money over the last year by giving advice or encouragement that I can take on some repair to a car/truck/tractor that I might have given to a mechanic otherwise.

Subject today is my '94 GMC Suburban with 350 CI engine.

Anyway, last night my AC compressor clutch or maybe the compressor itself froze up and started to fry the serpentine belt. I parked the vehicle safely and left it since it was after dark. Am going to try to limp it home (about 5 miles) later this morning. Called my local parts house and found that the clutch alone is about $90 and the clutch/compressor assembly is ~$150. Am thinking I would probably just do the whole thing, but wondering what I need to do about the refrigerant system. I don't have equipment to pump it down etc. so I know the tree huggers will not be happy about me releasing it, but I am more worried about the recharge. Can I just pull the compressor, replace it, hook things up again, and recharge or do I need to pull a vaccuum on the system to remove moisture, etc.

Otherwise, if I can determine that it is just the clutch can I replace that without removing the compressor as a whole? This of course would alleviate the refrigerant concerns.

All help is appreciated.

TIA,

Kirk

I ran out of time yesterday (and repair was starting to sound a little more involved than I had time or equipment to handle) and now am into the week so am getting the 'burb towed to my mechanic.

In the category of "When It Rains It Pours" I was doing a little light loader work with my Ford 3600 yesterday and the front spindle broke. Had a shimmy for a little while and was actually going to set aside time before winter to do a little work on it. Just got accellerated a bit. Not sure yet how I am going to get the half of the shaft out that is still in the wheel hub.

Thanks,

Kirk

If it is burnin' the belt, you probably need the whole unit; you have to drain it, flush it, and recharge. Most fellas like to replace the receiver and oriface tube while they are at it because these items are contaminated.

Also, You can't start it again until you repair it so take a trailer along to haul it home. It will not crank with that frozen compressor unless you take the belt off.

Allan

If the compressor has been working, and is not leaking refrigerant, it may be worth repairing, IF you can do it yourself, or have someone with the tools that will do it reasonably.

There is a nut on the compressor shaft, down in the recess at the center of the pulley that must be removed. Then, a special puller is screwed in the clutch hub, and the hub gets pulled off. That will expose the snap ring that holds the clutch pulley bearing to the compressor's "snout". Remove the snap ring. Usually, the bearing and pulley will come off reasonably easy. Otherwise, there is a special puller for that, to. (You CANNOT remove the clutch hub without the proper puller, and NEVER try to pull the pulley off by pushing agains the compressor shaft, or pound on the compressor shaft, as you will destroy the shaft see, and lose the refrigerant.)

Once you have the pulley off, you will find that the pulley is "staked" around the periphery of the bearing, to hold it in place.

You can buy a new or rebuilt pulley, with the bearing in place, or if you're CHEAP like me, carefully use a Dremel tool to grind off the "staked" metal and press out the bearing, and press in a new one, using high strength LockTite bearing retaining compound.

The bearing will not be listed for that application, but is the same part number as a late 50's to early 80's GM A-6 compressor clutch bearing.

Cost to repair, if you can borrow the tools , or get cheap help, about $20.00 for the bearing, or as you have found out, closer to $100, if you buy the complete clutch pulley.

Thanks for the very detailed and obviously informed reply.

Kirk

The screen in the dessicant/drier assembly broke and released the dessicant beads all through your system which jammed the compressor. Unplug the electrical connector from the compressor to disable the clutch and you'll be able to drive it home. Once home, take off the belt, engage the clutch with jumper wires (polarity doesn't matter) and turn the pulley by hand. If you feel gravel in either direction, then this is what happenned.

In this case you'll need a new compressor and drier assembly, the system must be flushed and you'll need to clean the gravel out of the orifice tube (just upstream of the evaporator coil (the cold one).

Hope this helps