AC Repair
Thread Starter
Pro
Joined: Apr 2001
Posts: 744
Likes: 13
From: Lenoir City TN
AC Repair
I have a 91 that I am in the process of repairing. It has been previously converted to R134. I am replacing the compressor with a new Denso OEM unit. The new compressor is marked R12 on the name plate. My question is should I drain the oil in the new compressor, slosh some flush fluid in it and then replace with the proper amount of new oil for R134? I intend on flushing the hole system and putting a new Dryer and accumulator valve in it.
Thanks
Thanks
Instructor
Joined: Dec 2004
Posts: 231
Likes: 0
I have a 91 that I am in the process of repairing. It has been previously converted to R134. I am replacing the compressor with a new Denso OEM unit. The new compressor is marked R12 on the name plate. My question is should I drain the oil in the new compressor, slosh some flush fluid in it and then replace with the proper amount of new oil for R134? I intend on flushing the hole system and putting a new Dryer and accumulator valve in it.
Thanks
Thanks
Last edited by badabing9; Jan 8, 2008 at 08:12 AM. Reason: spelling
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Drain out what's in it as you don't know what it is. Refill with 4 ozs of Ester or PAG (I'd go with Ester) and turn the shaft a dozen or so times in one direction, then the other. Drain and repeat. Then leave 4 ozs of fresh in it.
R134 has a smaller molecule so the tendency is to cram too much in it. If you're going to stick with R134, use 80% of the R12 charge which is 2.25 lbs or whatever the sticker says on the Evaporator Box. Oil capacity is 8 ozs, put the other half in a new Accumulator.
If you want to go back to R12, get your license to buy it at www.epatest.com and buy to your heart's content. Stay away from the golddiggers - try Autozone or NAPA. Even if you pay 20 Bucks/lb, that's a far cry from the $500 you probably forked out for a new Nippo compressor - sans the clutch assembly if it's from a GM Dealer.
I wouldn't try to charge anything up until it's 70 degrees or better, but if you do, recheck everything once the weather gets hot.
If your old compressor had a leaking shaft seal, that puts a lot a wear on it and all that metal is now lodged in the orifice. Charge it without cleaning it and it isn't going to cool very well regardless of what gas you put in it.
R134 has a smaller molecule so the tendency is to cram too much in it. If you're going to stick with R134, use 80% of the R12 charge which is 2.25 lbs or whatever the sticker says on the Evaporator Box. Oil capacity is 8 ozs, put the other half in a new Accumulator.
If you want to go back to R12, get your license to buy it at www.epatest.com and buy to your heart's content. Stay away from the golddiggers - try Autozone or NAPA. Even if you pay 20 Bucks/lb, that's a far cry from the $500 you probably forked out for a new Nippo compressor - sans the clutch assembly if it's from a GM Dealer.
I wouldn't try to charge anything up until it's 70 degrees or better, but if you do, recheck everything once the weather gets hot.
If your old compressor had a leaking shaft seal, that puts a lot a wear on it and all that metal is now lodged in the orifice. Charge it without cleaning it and it isn't going to cool very well regardless of what gas you put in it.
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