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Registered
1984 380SL
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98 Posts
Discussion Starter #1
After sitting a while, my AC compressor makes a fairly noticeable squeal when running. I am assuming that the bearings may have lost their lubrication. Is there any way to service the compressor without having to remove the refrigerant and compressor? I have disconnected the belt so it is currently not running.
D.
 

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Premium Member
2007 ML320CDI, 1959 220SE, 1971 280SL, 1982 380SL
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627 Posts
The bearings are internal and are lubricated with the circulating lubricant, so no work or lubrication is possible. Is this a continuous squeal? Clutches can make noises if slipping. Clutches can slip if the compressor is locking up and also a drive belt too loose can cause a clutch to slip. First thing to check is the drive belt tension. There is a bearing in the clutch which can make noise when the clutch is not engaged. If this is the case, the noise should stop when the AC clutch is activated.

If your noise is actually internal, no service is possible, and the concern would be that it is sending ground up metal through the system which would require a total dismantle and flush. Replacement A6 compressors these days are not what they were in days past. Delco no longer services them and the rebuilders now get their parts from China suppliers with quality often not the same as what was available before in the US parts chain. I find that quality and longevity for rebuilt compressors is very hit and miss. A replacement with an aftermarket Pro6ten compressor has been the most successful these days.

Replacement can be a significant amount of work.
 

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Registered
1981 380sl
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1 Posts
The bearings are internal and are lubricated with the circulating lubricant, so no work or lubrication is possible. Is this a continuous squeal? Clutches can make noises if slipping. Clutches can slip if the compressor is locking up and also a drive belt too loose can cause a clutch to slip. First thing to check is the drive belt tension. There is a bearing in the clutch which can make noise when the clutch is not engaged. If this is the case, the noise should stop when the AC clutch is activated.

If your noise is actually internal, no service is possible, and the concern would be that it is sending ground up metal through the system which would require a total dismantle and flush. Replacement A6 compressors these days are not what they were in days past. Delco no longer services them and the rebuilders now get their parts from China suppliers with quality often not the same as what was available before in the US parts chain. I find that quality and longevity for rebuilt compressors is very hit and miss. A replacement with an aftermarket Pro6ten compressor has been the most successful these days.

Replacement can be a significant amount of work.
here in phoenix
The bearings are internal and are lubricated with the circulating lubricant, so no work or lubrication is possible. Is this a continuous squeal? Clutches can make noises if slipping. Clutches can slip if the compressor is locking up and also a drive belt too loose can cause a clutch to slip. First thing to check is the drive belt tension. There is a bearing in the clutch which can make noise when the clutch is not engaged. If this is the case, the noise should stop when the AC clutch is activated.

If your noise is actually internal, no service is possible, and the concern would be that it is sending ground up metal through the system which would require a total dismantle and flush. Replacement A6 compressors these days are not what they were in days past. Delco no longer services them and the rebuilders now get their parts from China suppliers with quality often not the same as what was available before in the US parts chain. I find that quality and longevity for rebuilt compressors is very hit and miss. A replacement with an aftermarket Pro6ten compressor has been the most successful these days.

Replacement can be a significant amount of work.
a search revealed that ac compressor for your car is anywhere from 100.00us to 500.00us for brand new oem. my ac guy told me the ac compressor is exactly the same one in a chev camaro from the same year and cost much less.
 

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Registered
1984 380SL
Joined
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98 Posts
Discussion Starter #4
The bearings are internal and are lubricated with the circulating lubricant, so no work or lubrication is possible. Is this a continuous squeal? Clutches can make noises if slipping. Clutches can slip if the compressor is locking up and also a drive belt too loose can cause a clutch to slip. First thing to check is the drive belt tension. There is a bearing in the clutch which can make noise when the clutch is not engaged. If this is the case, the noise should stop when the AC clutch is activated.

If your noise is actually internal, no service is possible, and the concern would be that it is sending ground up metal through the system which would require a total dismantle and flush. Replacement A6 compressors these days are not what they were in days past. Delco no longer services them and the rebuilders now get their parts from China suppliers with quality often not the same as what was available before in the US parts chain. I find that quality and longevity for rebuilt compressors is very hit and miss. A replacement with an aftermarket Pro6ten compressor has been the most successful these days.

Replacement can be a significant amount of work.
The squeal is continuous. I disconnected the belt for that reason.
 

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Registered
1984 380SL
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98 Posts
Discussion Starter #5
here in phoenix

a search revealed that ac compressor for your car is anywhere from 100.00us to 500.00us for brand new oem. my ac guy told me the ac compressor is exactly the same one in a chev camaro from the same year and cost much less.
That is interesting. I'll have to look into that!
 

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Registered
1984 380SL
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98 Posts
Discussion Starter #6
The car still has the R12 refrigerant, so I may do a complete rebuild at some point.
 

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Premium Member
2007 ML320CDI, 1959 220SE, 1971 280SL, 1982 380SL
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627 Posts
R12 is certainly best. Dont use straight R134. Some of the after market blends seem to perform reasonably well.
 

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Registered
1984 380SL
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98 Posts
Discussion Starter #9
I have no fear of ripping the guts out of an engine, getting elbow deep in oil, grease and grime. But, I've never worked on an AC system. That being said, I am assuming that to replace my compressor, I would have to drain the system.
 

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Premium Member
1983 380SL, 2000 S430, 1991 420SEL (retired) - RHD
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5,371 Posts
I have no fear of ripping the guts out of an engine, getting elbow deep in oil, grease and grime. But, I've never worked on an AC system. That being said, I am assuming that to replace my compressor, I would have to drain the system.
Yes, you have to replace all your gas refrigerant..Probably a good idea to replace the peripheral bits and the hoses too.
 

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'88 560SL, '19 AMG E53 Cpe, '15.5 Volvo XC60, '53 MG TD, '35 Ford Cpe and a few more
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195 Posts
It's a good idea to replace the drier after the system has been opened also. And don't forget to add a bit of oil if replacing the compressor.
 
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