AC Compressor Clutch Failure
Thread Starter
Cruising
Joined: Mar 2015
Posts: 12
Likes: 0
AC Compressor Clutch Failure
Hi all,
I turned on the AC briefly today and was met with a small amount of smoke in the interior. I shut the car off and had a look. Looks like the clutch on the compressor bit the dust and threw black oil all over the place. I drove home with the AC off and haven't turned it on since. My question is whether I can just replace the clutch, or if an entire new AC system (including compressor) is in order. I haven't dug into it yet, but I plan on removing the belt and seeing if the compressor spins freely or if it has seized. If it does spin freely, should I replace the clutch and see what happens? Or does it not matter whether it spins freely at this point? Just looking for your thoughts, I guess. Thanks
I turned on the AC briefly today and was met with a small amount of smoke in the interior. I shut the car off and had a look. Looks like the clutch on the compressor bit the dust and threw black oil all over the place. I drove home with the AC off and haven't turned it on since. My question is whether I can just replace the clutch, or if an entire new AC system (including compressor) is in order. I haven't dug into it yet, but I plan on removing the belt and seeing if the compressor spins freely or if it has seized. If it does spin freely, should I replace the clutch and see what happens? Or does it not matter whether it spins freely at this point? Just looking for your thoughts, I guess. Thanks
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You don't have to take off the belt to check for free rotation of the compressor. If the clutch is not engaged then the pulley is not connected to the compressor. You can just turn the center part of the clutch, which is attached to the compressor.
Thread Starter
Cruising
Joined: Mar 2015
Posts: 12
Likes: 0
Thanks. I'll have a look this evening. Am I wrong to think that if I was able to drive 20 miles home without damaging the belt, the compressor must be spinning freely, even though I never used the AC during the trip home? Even when the clutch is not engaged, the belt is still spinning the compressor, right? Looking at the service manual, it looks like I should be able to replace the clutch without emptying the system, but would it do any good?
This is a 1992 with original AC system, I forgot to mention.
This is a 1992 with original AC system, I forgot to mention.
Burning Brakes
Joined: Dec 2014
Posts: 1,038
Likes: 44
From: Pensacola Florida
The belt is not turning the compressor if it is switched off. Only by turning on the A/C should the clutch engage. It also doesn't stay engaged 100% of the time while working but should cycle on and off periodically.
The black stuff is probably fried belt. Let us know what you find out.
Rick
The black stuff is probably fried belt. Let us know what you find out.
Rick
Racer
Joined: Jul 2007
Posts: 379
Likes: 12
From: Huntsvegas AL
Replaced my AC compressor clutch coil and pulley in this thread:
https://www.corvetteforum.com/forums/...errerid=258253
The black goo is probably either melted plastic from the coil ( behind the pulley) or the rubber gasket inside the clutch itself. On my car everything melted resulting in a big mess.
Only the pulley is spinning when the compressor is off. The coil has to be energized to engage the clutch which will then rotate the compressor.
https://www.corvetteforum.com/forums/...errerid=258253
The black goo is probably either melted plastic from the coil ( behind the pulley) or the rubber gasket inside the clutch itself. On my car everything melted resulting in a big mess.
Only the pulley is spinning when the compressor is off. The coil has to be energized to engage the clutch which will then rotate the compressor.
Thread Starter
Cruising
Joined: Mar 2015
Posts: 12
Likes: 0
I took the belt off and had a closer look. The belt looks great and I was able to turn the clutch by hand without much effort. I'm still not sure what the black stuff is, but If you take a closer look at the picture, it looks like the source is from under the clutch plate. You can see the evidence of dried oil/goo, which looks like it was flung out from underneath the plate as the compressor was spinning. After a little more research, I'm guessing a shaft seal? Regardless, I think I'm just going to throw on a AC delete pulley and call it a day. This is a weekend toy and the roof panel is off 90% of the time, so I'd rather forget about it than potentially pour $600+ into replacing the entire system as I rarely use it.
Off to the parts forum to see if I can find a delete pulley! Thanks
Off to the parts forum to see if I can find a delete pulley! Thanks
Burning Brakes
Joined: Dec 2014
Posts: 1,038
Likes: 44
From: Pensacola Florida
I took the belt off and had a closer look. The belt looks great and I was able to turn the clutch by hand without much effort. I'm still not sure what the black stuff is, but If you take a closer look at the picture, it looks like the source is from under the clutch plate. You can see the evidence of dried oil/goo, which looks like it was flung out from underneath the plate as the compressor was spinning. After a little more research, I'm guessing a shaft seal? Regardless, I think I'm just going to throw on a AC delete pulley and call it a day. This is a weekend toy and the roof panel is off 90% of the time, so I'd rather forget about it than potentially pour $600+ into replacing the entire system as I rarely use it.
Off to the parts forum to see if I can find a delete pulley! Thanks
Off to the parts forum to see if I can find a delete pulley! Thanks
I would be sure to figure out away to make sure the evaporator core doesn't corrode while it's exposed to the climate, that will just be added expense if you decide to reinstate the A/C.
Also the A/C has a bearing on your defroster/defogger, not sure how much but it does run in that mode.
Rick
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
It's always a good idea to at least give your year! The black goo is most likely bearing grease escaping from a worn out grease seal. In order to verify this you will need to remove the Clutch "Driven Plate" by removing the center Fastener, and very carefully slide the plate toward you, while capturing any Shims that may fall out. Once the Driven Plate has been removed you will see the "Pulley" Bearing held in place by a snap ring.. This would be the area to inspect for escaping bearing grease.
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Thread Starter
Cruising
Joined: Mar 2015
Posts: 12
Likes: 0
I'm in Columbia, SC. Not pleasant at the peak of summer, but I'll manage! It's really just something to cruise around in with the top off occasionally. I'd never daily this thing. I was only taking a short trip and was too lazy to remove the top only to screw it back on 5 minutes later, so I just figured I'd turn the AC on for my short trip.
The picture of the underside of the hood doesn't show it that well, but there's a line of white residue running parallel to the black gunk. It's not anywhere else under the hood, and since it's in the same spot, I'm thinking it might be where R12 rushed out of the compressor and hit the hood? Maybe not, I don't know much about this.
My biggest concern is when it comes time to sell... resell value definitely just took a hit. Could always be worse, I guess!
The picture of the underside of the hood doesn't show it that well, but there's a line of white residue running parallel to the black gunk. It's not anywhere else under the hood, and since it's in the same spot, I'm thinking it might be where R12 rushed out of the compressor and hit the hood? Maybe not, I don't know much about this.
My biggest concern is when it comes time to sell... resell value definitely just took a hit. Could always be worse, I guess!