Would a Free-wheeling A6 A/C Compressor Seize?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Would a Free-wheeling A6 A/C Compressor Seize?
Right now the drive belt is off my 1974 A6 A/C compressor. The A/C has been non-functional since I bought the car a couple of years ago. I disconnected and tucked away the electrical connections so they remain intact.
Being a convertible I generally drive with the top down (unless it rains) and have no need for A/C. In fact I can count on one hand the number of days in the past few summers when temps went over 30*C (86*F): this is not a heat zone. On cooler days I just flick on the heater.
I had thoughts of removing the A/C system but that really takes away from a car's attributes, even if not working. I also had thoughts of having it repaired but given the possibility of very limited use, and the very substantial costs I might face including mandated R-134 conversion, that does not appeal.
But just to give the "appearance" of the car being whole I was thinking of putting the A/C belt back on. I have a new one in the basement inventory. The compressor pulley moves freely by hand so it is still operable in that sense. If the belt is put back on is there any chance the compressor, although free-wheeling and with no electrical power, will seize even without the clutches kicking in as with normal use?
Appreciate your comments!
Being a convertible I generally drive with the top down (unless it rains) and have no need for A/C. In fact I can count on one hand the number of days in the past few summers when temps went over 30*C (86*F): this is not a heat zone. On cooler days I just flick on the heater.
I had thoughts of removing the A/C system but that really takes away from a car's attributes, even if not working. I also had thoughts of having it repaired but given the possibility of very limited use, and the very substantial costs I might face including mandated R-134 conversion, that does not appeal.
But just to give the "appearance" of the car being whole I was thinking of putting the A/C belt back on. I have a new one in the basement inventory. The compressor pulley moves freely by hand so it is still operable in that sense. If the belt is put back on is there any chance the compressor, although free-wheeling and with no electrical power, will seize even without the clutches kicking in as with normal use?
Appreciate your comments!
Le Mans Master
Joined: Jun 2007
Posts: 7,666
Likes: 1
From: Where it's always hot as Hell-South Louisiana.
St. Jude Donor '07-'08-'09-'10-'11-'12-'13
It takes voltage applied to the clutch to make the compressor crankshaft begin to turn. The answer is :NO.....Just make sure you tuck the electrical connection (unplugged) away from the compressor.
There will be a minimal h.p. loss just by rotating the belt on the compressor. I doubt that the loss could be measured since it's so small. Just make sure the compressor will never see a voltage signal to pull the clutch in.
It's all in viewpoint, as I just took all my stuff off the engine when I put in a new crate motor. Left the evap coil and box, everything else is toast...
There will be a minimal h.p. loss just by rotating the belt on the compressor. I doubt that the loss could be measured since it's so small. Just make sure the compressor will never see a voltage signal to pull the clutch in.
It's all in viewpoint, as I just took all my stuff off the engine when I put in a new crate motor. Left the evap coil and box, everything else is toast...
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
It takes voltage applied to the clutch to make the compressor crankshaft begin to turn. The answer is :NO.....Just make sure you tuck the electrical connection (unplugged) away from the compressor.
There will be a minimal h.p. loss just by rotating the belt on the compressor. I doubt that the loss could be measured since it's so small. Just make sure the compressor will never see a voltage signal to pull the clutch in.
It's all in viewpoint, as I just took all my stuff off the engine when I put in a new crate motor. Left the evap coil and box, everything else is toast...
There will be a minimal h.p. loss just by rotating the belt on the compressor. I doubt that the loss could be measured since it's so small. Just make sure the compressor will never see a voltage signal to pull the clutch in.
It's all in viewpoint, as I just took all my stuff off the engine when I put in a new crate motor. Left the evap coil and box, everything else is toast...
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
The pulley is on a bearing mounted to the front of the compressor.
It is possible that this bearing could fail and seize while not using the compressor.
I've changed a few of these bearings over the years; it’s not a hard job with the right tools.
The compressor will have no effect on the operation of the pulley as long as the clutch is not energized.
After reading your question again I'm not sure I understand what you’re asking. Are you asking if the compressor could seize from not using it or are you concerned that the pulley could seize from having the belt spinning it?
Neal
It is possible that this bearing could fail and seize while not using the compressor.
I've changed a few of these bearings over the years; it’s not a hard job with the right tools.
The compressor will have no effect on the operation of the pulley as long as the clutch is not energized.
After reading your question again I'm not sure I understand what you’re asking. Are you asking if the compressor could seize from not using it or are you concerned that the pulley could seize from having the belt spinning it?
Neal
Last edited by chevymans 77; Apr 24, 2011 at 12:30 AM. Reason: clarefication
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
The pulley is on a bearing mounted to the front of the compressor.
It is possible that this bearing could fail and seize while not using the compressor.
I've changed a few of these bearings over the years; it’s not a hard job with the right tools.
The compressor will have no effect on the operation of the pulley as long as the clutch is not energized.
After reading your question again I'm not sure I understand what you’re asking. Are you asking if the compressor could seize from not using it or are you concerned that the pulley could seize from having the belt spinning it?
Neal
It is possible that this bearing could fail and seize while not using the compressor.
I've changed a few of these bearings over the years; it’s not a hard job with the right tools.
The compressor will have no effect on the operation of the pulley as long as the clutch is not energized.
After reading your question again I'm not sure I understand what you’re asking. Are you asking if the compressor could seize from not using it or are you concerned that the pulley could seize from having the belt spinning it?
Neal
The latter. Is there a possibility that the pulley could seize from having the belt turning it (but no load from the clutch).
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
Hey Paul, all the guys are correct. Put the belt on it and see if the clutch bearing is noisey. They normally schreech for several miles/days before they lock up. In Canada, it is mandatory to convert to R-134A? mike...
Last edited by mds3013; Apr 24, 2011 at 07:54 AM.
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Drifting
Joined: Apr 2002
Posts: 1,743
Likes: 37
From: Stockton Ca
Same Problem!
I have had two compressors lock up on my 74. The first time was bc it was not "cycling" properly?
The next was a mystery. Yesterday I wanted to fire off the beast for the spring. No starting and the best is squealing. I'm going to pull the best this morning and try again. There has to be a fix that lasts longer?
I have heard forum members say the compressor is old, big and heavy, but it is supposed to last. Not in my experience.
I'm not fixing this old outdated system until I can do it right. A whoe new aftermarket system is out of the question for now. I was hoping to get off w/new compressor? LOL We shall see.
R
The next was a mystery. Yesterday I wanted to fire off the beast for the spring. No starting and the best is squealing. I'm going to pull the best this morning and try again. There has to be a fix that lasts longer?
I have heard forum members say the compressor is old, big and heavy, but it is supposed to last. Not in my experience.
I'm not fixing this old outdated system until I can do it right. A whoe new aftermarket system is out of the question for now. I was hoping to get off w/new compressor? LOL We shall see.
R
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Many of the a/c belts had been removed because the pulley bearings were bad, not the compressor itself. You can test the pulley bearing by just turning it by hand to see if if it feels smooth.
If you are having compressors seize, then it either wasn't evacuated properly for moisture and then filled properly or the system had a leak.
Unlike most modern compressors, the a6 has an oil reservoir which helps in lubrication.
A later style seal can also be used to prevent the old tell tale front seal seepage problem. The downside is the shaft will eventually wear instead of just the seal.
They are still used in heavy duty applications.
If you are having compressors seize, then it either wasn't evacuated properly for moisture and then filled properly or the system had a leak.
Unlike most modern compressors, the a6 has an oil reservoir which helps in lubrication.
A later style seal can also be used to prevent the old tell tale front seal seepage problem. The downside is the shaft will eventually wear instead of just the seal.
They are still used in heavy duty applications.
Drifting
Joined: Apr 2002
Posts: 1,743
Likes: 37
From: Stockton Ca
Lack of Use?
I was told that if I just ran the AC more often, the system would hold coolant and need less work. I will check the bearings later today.
I agree that the car should be run, but sometimes that is not pratical.
I still want something that holds up better.
R
I agree that the car should be run, but sometimes that is not pratical.
I still want something that holds up better.
R
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
If I were to get serious about the A/C I would consider a Sanden compressor and the pressure hoses needed. It seems that Eckler's sells a light-weight replacement for the A6 - physically identical - but the $398 price does not appeal to me.
http://www.ecklers.com/corvette-comp...1963-1976.html
http://www.ecklers.com/corvette-comp...1963-1976.html
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