A/C compressor questions

John Burchfield

John Burchfield

PCS Life Member
When I got my '75 M-M combination back in 2007, the belt to the a/c compressor had been removed so I assumed the compressor was bad. Talking with my mechanic about it as recently as 2 years ago he said "oh those compressors are plentiful and not that expensive." Well it seems recently the price of these things has skyrocketed. A call yesterday to a few auto parts stores (Advance, Auto Zone, & NAPA) got quotes of 140-185.00 rebuilt & 420-483.00 new- yikes! My mechanic recommends a new one rather than rebuilt. So, does anyone know of a cheaper source for a new compressor, or perhaps have one stockpiled that they don't need? :) I was hoping to get the a/c working in time for our chapter meet/show at Pinehurst next weekend. Looking a little closer last night when I got to the barn I can turn the compressor by hand, but the ring behind the magnet portion of the clutch is loose. I don't have a belt yet for the compressor so I can't try it, but if I'm lucky maybe just the clutch is bad. The compressor appears to be the original one w/ AC Delco decal, etc. This is the long cylindrical type that was used from the 60s to at least mid 70s. Thanks for your help.
 
John Burchfield said:
When I got my '75 M-M combination back in 2007, the belt to the a/c compressor had been removed so I assumed the compressor was bad. Talking with my mechanic about it as recently as 2 years ago he said "oh those compressors are plentiful and not that expensive." Well it seems recently the price of these things has skyrocketed. A call yesterday to a few auto parts stores (Advance, Auto Zone, & NAPA) got quotes of 140-185.00 rebuilt & 420-483.00 new- yikes! My mechanic recommends a new one rather than rebuilt. So, does anyone know of a cheaper source for a new compressor, or perhaps have one stockpiled that they don't need? :) I was hoping to get the a/c working in time for our chapter meet/show at Pinehurst next weekend. Looking a little closer last night when I got to the barn I can turn the compressor by hand, but the ring behind the magnet portion of the clutch is loose. I don't have a belt yet for the compressor so I can't try it, but if I'm lucky maybe just the clutch is bad. The compressor appears to be the original one w/ AC Delco decal, etc. This is the long cylindrical type that was used from the 60s to at least mid 70s. Thanks for your help.
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John call me 734-368-8338

Russ
 
John, are you converting to 134-a when you get the compressor or staying with R-12? I saw where Jay Leno installed a rear A/C system in his 66 Tornado Oldsmobile.
 
From what you describe about your compressor, the clutch mechanism has worn out. It can be changed and a new front seal installed while it is still in the car if the mechanic has the proper tools and experience to do the job. If not, then you can purchase a rebuilt compressor with a new clutch installed. It all depends on how much you want to keep your car as originally built. If you decide to go the new compressor route, you can pay the core charge and keep the old compressor. The core charge is usually not more than $15, since they have plenty of cores already. The only valuable part on your car is the defective part. If you want to take your compressor off and send it out for repair, I suggest that you send it to Classic Auto Air in Tampa Florida. I have used them in the past and have been very happy with the service and quality of work.
 
Let us know what direction you end up going with this John. I have concerns on my Lifeliner and feel the best direction "for me" is to just upgrade the entire system so I have cool air. I mean a new modern compressor, fittings, evaporator, and controls. I'll just have to take the point deductions at shows but at least I have cold air.
 
A/C

I mean a new modern compressor
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Compressor on yours is one the of best compressors made. I replaced the front seal on my brothers car new fuse and 4lbs of R-12 and dam it only blows 42 degs.:thumb:

 
c.c. specific?

OK, here's a new wrinkle: Does the commercial chassis have a specific compressor? When I called Carquest they showed a different part no. for the c.c. vs. deVille/Fleetwood. Auto Zone and Advance don't make a distinction. When I put "Fleetwood 75" in the Auto Zone search (they don't list comm. chassis) the same compressor as for the deVille/Fleetwood came up. I'm running out of time and need to get one in the morning if I want to have air for the trip to Pinehurst on Thursday after work! The car is in the shop waiting. Also fyi, Auto Zone has a 3 mo. warranty on rebuilt compressors, Advance and CarQuest offer 1yr. on probably the exact same compressor. One more thing, my mechanic agreed that the A6 is one of the best compressors and said that a rebuilt one is probably fine-it's the newer aluminum compressors and similar parts that he's had bad luck with using rebuilt units.:17875:
 
Parts book doesn't differentiate between models and lists all from 1958 to 1975 with a single part number for the service replacement. I do know that Robert Shepard had a problem using a compressor from a 1976 on his 1975, because the bolt holes didn't match up to his brackets. He had to use the the brackets from the 1976 on his 1975 engine to make it fit properly. It is one of those slight changes that will bite you every time. I suggest that your mechanic carefully check this before he proceeds and I would keep the old compressor in case you ever need it in the future. The core charge isn't that much that it is worth turning in. Besides, they might not even accept it for a rebuild-able core since the most valuable part, the clutch assembly is not functional.......
 
if your going to spend the money on the AC you might as well spend it on the components the car came out with. Rebuilt is Ok and one year is better the 90 days. I don't know of any difference in the CC car then the standard fleet wood. just remind them to add the can of sealer to.
 
I will disagree with Ed on the sealer. If you ever need to have the air conditioner serviced again, and it has sealer in it, there isn't anyone that is going to want to do the service. The sealer is the kiss of death to the air conditioning service machines, and they are very expensive. The sealer will also clog the vacuum pumps and ruin them. Putting sealer into a air conditioning system is a band aid approach to repair. If the system has a leak, find the leak and fix it properly.
 
I learned some things this afternoon talking w/ one of the technical advisors at Classic Air in Tampa. Sometime during the '73 model year, GM changed from separate receiver-dryer, suction valve, and accumulator to the VIR assembly that combined these components (Valves In Receiver, not Virginia International Raceway). This arrangement continued through 1976 models. In 1977 they adopted an accumulator type system that allowed the compressor to cycle on and off for greater efficiency. This is essentially the same system modern GM a/c uses. VIR systems are not compatible with upgrades to R134, but the good news is Classic Air sells a VIR eliminator kit (94.00, cheaper than rebuilding your VIR) that changes the setup to one more like the modern accumulator system. I think I have this right, but don't ask me to explain in more detail what an accumulator does! I ordered a kit so hopefully next week the '75 will have cool air!
 
My 1962 Chevrolet C/B has a GM factory air condition system like none I have ever experienced before. There is a valve under the right hand fender that causes the air conditioner compressor to cycle off and on depending on the pressures in the system. This valve is hooked up to a cable that is on the inside of the air conditioner console, and you pull on the cable to moderate the temperature of the air coming out of the diffuser. It also has a bulb attached to an electrical system device that I can't even find a reference to in the shop manual or the parts books. It is a one year only system, so I have my doubts as how well it works in practice. I have a feeling that this "bulb" and electrical device is a factory modification that was part of a service campaign to "fix" a performance issue. All I know is that the air conditioner will freeze you out of the car even on the hottest of days.
 
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