Compressor Rebuilder for '85 Using R12
Thread Starter
Safety Car
Joined: May 2003
Posts: 4,797
Likes: 239
From: Ocean Township NJ
Compressor Rebuilder for '85 Using R12
My R4 compressor needs a shaft seal kit. After slinging oil for 20 years, it has finally reached the point where it won't hold a charge for more than a few months. I want to remove it and ship to a reliable rebuilder. I need contact information. Also need a source for R12 Freon* to recharge the system.
***********OR********
Can I do it myself? The Service manual specifies about 1000 special tools required. How many of these are really necessary? This really HURTS, because I always do everything myself. I really don't want to invest in so many special tools. I will, however buy 2 or 3 tools, and do the job myself. This repair CAN be done without removal.
***********OR********
Can I do it myself? The Service manual specifies about 1000 special tools required. How many of these are really necessary? This really HURTS, because I always do everything myself. I really don't want to invest in so many special tools. I will, however buy 2 or 3 tools, and do the job myself. This repair CAN be done without removal.
Drifting
Joined: Jan 2001
Posts: 1,347
Likes: 4
From: Slidell La
I would recommend you consider buying a new compressor with warranty.
Changing is not that difficult if your compressor only has a seal problem and not sent metal particles into the system.
There are others who can reply on a replacement for R12,, but changing the compressor would make it a easy upgrade to 134a. Why not shop around for a new compressor then determine which freon to use. Also,, do you have a vacuum pump.? This is needed to evacuate the system.
If you open it up to change compressor and it is an 85,, you might want to change there dryer also. 99 Nassau Blue
Changing is not that difficult if your compressor only has a seal problem and not sent metal particles into the system.
There are others who can reply on a replacement for R12,, but changing the compressor would make it a easy upgrade to 134a. Why not shop around for a new compressor then determine which freon to use. Also,, do you have a vacuum pump.? This is needed to evacuate the system.
If you open it up to change compressor and it is an 85,, you might want to change there dryer also. 99 Nassau Blue
Thread Starter
Safety Car
Joined: May 2003
Posts: 4,797
Likes: 239
From: Ocean Township NJ
Originally Posted by jimcork1
I would recommend you consider buying a new compressor with warranty.
Changing is not that difficult if your compressor only has a seal problem and not sent metal particles into the system.
There are others who can reply on a replacement for R12,, but changing the compressor would make it a easy upgrade to 134a. Why not shop around for a new compressor then determine which freon to use. Also,, do you have a vacuum pump.? This is needed to evacuate the system.
If you open it up to change compressor and it is an 85,, you might want to change there dryer also. 99 Nassau Blue
Changing is not that difficult if your compressor only has a seal problem and not sent metal particles into the system.
There are others who can reply on a replacement for R12,, but changing the compressor would make it a easy upgrade to 134a. Why not shop around for a new compressor then determine which freon to use. Also,, do you have a vacuum pump.? This is needed to evacuate the system.
If you open it up to change compressor and it is an 85,, you might want to change there dryer also. 99 Nassau Blue
Mechanically, the compressor/clutch hub is fine, in fact it works, but cycles because of low refrigerant, so a shaft seal is really all that it needs.
I do not (yet) have a vac pump, but can easily get one from Harbor Freight. If I change over to R134a, I understand that I must install different charge fittings on the high and low side. I must also remove the old compressor oil from the accumulator. Here are a few questions:
1. Are there any other changes i.e. : different orifice size for expansion valve?
2. Will the system blow as cold with the 134a?
3. Must I flush out all of the old compressor oil? I understand that it is not compatible with 134a.
4. Do the new charge fittings simply screw into the originals? Reason I ask, is that I would remove them after the recharge, to maintain "originality".
5. Is the shaft seal kit still available from GM?
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
The R4 compressor requires several special tools to properly disassemble and reassemble. I found a local mechanic who did a/c work as well as other repairs, who had a complete set of these tools in his shop. He wouldn't loan them to me but, for a few bucks, he would use his tools to perform whatever task I needed at that time. This obviously took several trips to his shop, but that wasn't too big a deal, as I drove by it every day, to and from work. They are rather simple mechanical devices once disassembled and parts are redably available.
As far as NCRS judging goes, the only marks on the Compressor which are judged, are the printed model number and stamped date code on the lable. If you can find a source for a new lable with the correct markings (I have purchased one for my restored 1980, L82) the actual compressor can be switched out for a new one, with no visable evidence that a switch has occured. I got mine from DR. Rebuild. When done, I couldn't tell it from the original.
As far as NCRS judging goes, the only marks on the Compressor which are judged, are the printed model number and stamped date code on the lable. If you can find a source for a new lable with the correct markings (I have purchased one for my restored 1980, L82) the actual compressor can be switched out for a new one, with no visable evidence that a switch has occured. I got mine from DR. Rebuild. When done, I couldn't tell it from the original.
Last edited by Strike3; Apr 23, 2005 at 12:34 PM.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
You might try www.ackits.com for tools and a seal kit or call them to determine if they can rebuild your original.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Originally Posted by 65tripleblack
1. Are there any other changes i.e. : different orifice size for expansion valve?
2. Will the system blow as cold with the 134a?
3. Must I flush out all of the old compressor oil? I understand that it is not compatible with 134a.
4. Do the new charge fittings simply screw into the originals? Reason I ask, is that I would remove them after the recharge, to maintain "originality".
5. Is the shaft seal kit still available from GM?
2. Subject of much debate. I get 41-45 degrees at the vent in 100 degree ambient. I don't remember it being any colder with R12.
3. Absolutely. Mineral oil and PAG oil are NOT compatible. If you mix them, your compressor will die a noisy smoky death as the mixture turns to a carmel like substance.
4. Yes. You can remove the adaptors once you charge it. Nobody will be the wiser. I never bothered to install the high side adaptor. Good time to change out the needle valve on the high side while it's empty also.
5. I have no idea. I vote for changing compressors and doing what Strike said. The judges won't look inside of it.
Remember if you're retrofitting to R134A to change out the O rings and accumulator / drier (with low side fitting for charging), and to then vacuum the system to remove any residual mineral oil and moisture. Use PAG oil, and charge to 80% of R12 rating with automotive R134A.
Convert, and never look back.
[edit]...should have said accumulator / drier, not evaporator.
Last edited by Frizlefrak; Apr 23, 2005 at 11:58 PM.
Thread Starter
Safety Car
Joined: May 2003
Posts: 4,797
Likes: 239
From: Ocean Township NJ
Thank you all for the information. I'm absolutely favoring conversion to 134a. Why put it off, really, because it would be foolish to pay the high prices of R12 unneccessarily. That is, so long as 134a performs as well as or better than R12 in a system designed for R12.
I will call Arizona Mobile Air this week. Changing out the R4 is not a problem so long as it cannot be detected as a replacement. As far as the label goes, I can find a way to transfer it to the new compressor.
The compressor oil is what baffles me. Do I understand you to mean that all traces of the original (mineral) oil must be removed? Does this mean that the entire sealed system must be dismantled and meticulously flushed out, including the EVAPORATOR?
I am now thinking in terms of DOT 4 and DOT 5 brake fluids, which are not compatible, and ALL traces of either must be removed before introducing the other.
I will call Arizona Mobile Air this week. Changing out the R4 is not a problem so long as it cannot be detected as a replacement. As far as the label goes, I can find a way to transfer it to the new compressor.
The compressor oil is what baffles me. Do I understand you to mean that all traces of the original (mineral) oil must be removed? Does this mean that the entire sealed system must be dismantled and meticulously flushed out, including the EVAPORATOR?
I am now thinking in terms of DOT 4 and DOT 5 brake fluids, which are not compatible, and ALL traces of either must be removed before introducing the other.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Originally Posted by 65tripleblack
The compressor oil is what baffles me. Do I understand you to mean that all traces of the original (mineral) oil must be removed? Does this mean that the entire sealed system must be dismantled and meticulously flushed out, including the EVAPORATOR?
http://www.delanet.com/%7Epparish/flushing.htm
There really isn't a good way to flush the accumulator / drier. It's best to replace it. It can collect residual oil, moisture, and contaminants. It's relatively inexpensive, best to just replace it. Then remember to pull a vacuum on the entire system.
Last edited by Frizlefrak; Apr 23, 2005 at 11:59 PM.
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Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
This morning, in Advanced Auto Parts, in the air conditioning stuff section, I saw a can of fulsh which had a hose rolled up in the cap and instructions on how to flush your system. I read the instructions and it seemed straight forward and rather simple. Look around your favorit auto parts store at all the refigerant, compressor oils, addiives etc. You may find a lot of answers.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
While it's a good idea to flush (and it's pretty much mandatory to swap out the accumulator anytime you open it up), you can use Ester instead of PAG and not have to worry about compatibility. If using PAG, stick with Mineral on the o-rings, it doesn't have the same affinity for water. In line filters can be installed too, forward of the condensor, but before the orifice, though I can understand that you might not want one if you plan to keep it OEM. Speaking of the accumulator, some OEM replacements (GM uses the same on a number of applications, some of which mount the low pressure switch on the accumulator) come with two service ports and the retainer bracket has to be notched to keep it from hitting the hood. The closest, identical replacement, I've found was at NAPA. Before buying, you might want to look at the OEM replacement at www.acdelco.com - especially if you mail order the part.
Drifting
Joined: Jan 2001
Posts: 1,347
Likes: 4
From: Slidell La
Frizelfrak is right on. but you must flush the oil. If you rebuild the compressor,, you can use the new oil. The R/dryer should be replaced. You can also use the a/c flush. I bought from JCwhitney a pressure container that is pressurized with a air compressor after you add the flush. Then you can pressure flush the entire system. I have used this on a Lincoln where the compressor sent metal through out the system. It took about 3 qts of flush to clean it up and the flush is $$$.. but it did work. 99 Nassau Blue
Messy flushing,,
Messy flushing,,
