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Corvair Compressor

junkman on Sun July 19, 2015 11:13 PM User is offline

Year: 1963
Make: Chevrolet
Model: Corvair Monza
Engine Size: 145 C.I.
Refrigerant Type: R12
Ambient Temp: n/a
Pressure Low: n/a
Pressure High: n/a
Country of Origin: United States

I had a loose hose clamp, and lost the refrigerant in my system, and what I found was that the old rubber hoses had become so hard, and the clamps were not sealing the system properly. As I result, I have decided to re-hose the entire system with new barrier hose, and to install fresh oil and refrigerant after I flush the system. I did lots of mobile air systems back in the 1960's and early 1970's until I changed professions, and I still have all of my old tools. After doing some research, I found that there came a time that GM started adding a felt wick to the compressor clutch pulley. When I was doing this work, I don't remember if I ran into compressors with wicks or not. The 1963 Corvair that I am presently working on, doesn't have this wick, and it doesn't appear that there is a place to install it. My question is, when did GM start installing the wick, and is it possible to get a latter pulley that has this provision in it for the wick? Also, are the wicks available as a separate item, without buying the complete seal kit. Thanks for any help that you can give me to keeping my car cool..

CorvairGeek on Mon July 20, 2015 8:00 AM User is offline

Even though the compressor is CCW rotation on the Corvair, I thought the clutch and pulley assy was one of the parts that did interchange with interchange with other GM cars. When I have changed GM compressors over to a double lip seal, I have not added the white felt when reassembling because they don't sling oil anymore, and I wanted to see if they did.


junkman on Tue July 21, 2015 5:26 PM User is offline

A few people have advised me that the double lip seals didn't leak at first, but then they started leaking mid way into the cooling season. One person attributed this to the "fact" that the shaft was slightly off center because of 50+ years ago manufacturing tolerances. What has been your experience?

CorvairGeek on Wed July 22, 2015 8:26 AM User is offline

I've personally had excellent service with my limited experience with them (10 years plus, A6, R4 and V5), GM Tech could better speak to his far more substantial experience. I would be skeptical of the 'manufacturing tolerance' theory as they were sealed with ceramic in production until '84 and I would think that it would be far less forgiving than the double lip seal. I would be more suspect of people trying to reseal worn compressors and expecting miracles, as well as installation techniques. If a Corvair compressor doesn't have the original 'Frigidaire' sticker on it anymore, i.e. been 'rebuilt', who knows what may have been done to it in the past 50+ years as well.


junkman on Sat August 01, 2015 3:18 PM User is offline

I was able to remove the clutch and pulley without any problems, however, after I got the snap ring off that held on the steel washer that covers the seal, I ran into problems. At this point, I decided that I would do a complete reseal of the compressor, and had no trouble disassembling it, and everything apart. I did find that there is some speckling of rust on the cover for the oil reservoir, and that the screen in the rear end plate had some debris. Upon closer examination, it appears that is was some rubber chips from when the hoses were cut on the assembly line. The front shaft has some rust on it, and I am wondering if it is OK to just clean it up with a Scotchbrite pad and oil? Below are some pictures that I took today to show the overall condition of the compressor. When I moved the pistons in the bores, there was no sign of wear, and the original honing marks were still visible. I don't believe that even though this compressor is 50 years old, that it has seen much use. The only part that I damaged is the small metal part in the last picture, which I believe is part of the seal, and will come with a new seal. There appears to be some slight rust pits on the front valve plate, but after going over it lightly with a razor blade and oil, they appear to be more "scars" than anything else. You can't feel them with your finger or fingernail. I would appreciate your thought on how to proceed. I am strongly leaning toward the use of the original type ceramic seal.





Edited: Sat August 01, 2015 at 3:33 PM by junkman

CorvairGeek on Sun August 02, 2015 9:44 AM User is offline

I've since read the ceramic seal is supposed to be more forgiving, but I don't understand why. I assume there may be a number of reasons that I may not recognize. With that said, from my experience and listening to GM Tech for many years, I would personally still use the double lip seal. My only concern might be if the seal rides in the area that is rusted. I don't recall exactly where it rides on the shaft, and if there is any (how ever small) difference in where the original 'bird cage' (ceramic) rides and where the new seal contacts. I'm sure GM tech knows exactly.

Other than leakage, was this compressor functioning well before disassembly?


junkman on Sun August 02, 2015 12:38 PM User is offline

I have no history of the compressor, since it came with some other spare parts. From my examination of the compressor, it appears that it has never been apart in the past. When I check the Chevrolet parts book from 1962, and then go to a later parts book, like 1966, I find that some of the original part numbers have been discontinued, and there are notes to dispose of those parts, and to replace them with the later part number. The biggest problem is trying to figure out the nomenclature of the part as to exactly what it is. I have deciphered some of this by checking with the original service manuals, and looking at the parts breakdown. For this reason, I know that I am going to need a later model compressor to get the newer parts. It is my intention to use the original compressor shell, and to update it with parts from a later model compressor. Right now, my concern is what to do with the shaft, as far as cleaning up the rust. The reasoning for using the original ceramic seal, is because I believe that ultimately, it will be an easier seal to use for me. I have done a lot of reading on the Corvette forums, where people have used the new double lip seal, and that it has failed them multiple times, and they go back to using the ceramic seal, with good results. It is my opinion, based on my reading at those forums, that the double lip seal works best with the later models of the A6 compressor. Upon removing the original seal in this compressor, I believe that there was no ceramic seal, only a black carbon seal, and the shaft seal seat, then the shaft seal retainer snap ring. I would like to know what year was the ceramic seal introduced. I know that 1962 was the first year for the field serviceable A6 compressor, and that the 1961 unit is totally different. I also don't know what year the field serviceable A6 was introduced to the other GM product line. I have also learned from the Chevrolet parts book, that the original clutch bearing changed sometime in 1963, however, I don't know it the new number is interchangeable with the old part number.

junkman on Mon August 10, 2015 10:56 PM User is offline

Bump.. Can someone give me some advise on what to do about the rust on the shaft? thanks Junkman

GM Tech on Tue August 11, 2015 7:19 AM User is offline

Emory cloth comes to mind...then polish with buffer....

The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

bohica2xo on Tue August 11, 2015 9:47 AM User is offline

I would clean that surface up with some Flitz and a shop rag. Remove as little material as possible. Avoid linear motion.

I have seen seals leak from linear or helical tool marks, and have seen others seal just fine against random small pits. You basically just have to polish it & try.

Building a compressor from parts will be tricky. There are a lot of A6's out there, and only a small number are reverse rotation

Most are 12.6 CID. All of the A6's supplied to Ford were 12.6 CID

The exceptions:

"MOST" Corvettes used a 10.8 CID compressor - there were a few exceptions.

All Corvairs used the 10.8 CID compressor, with the oil pump re-configured for reverse rotation.

"SOME" Vegas were fitted with the 10.8 CID compressor. Depending on delivery area, some had 12.6's, and POA valves.....


"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

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