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Discussion Starter #1
I found a 79 Sedan Deville in the loal junkyard (theres a severe shortage of Caddies in local junkyards) and it had the 425 and AC. The compressor looked to be in decent condition, the pulley moved freely and everything. My question is, will this compressor work on my 1970 Sedan Deville w/472. My compressor had to be removed because it siezed up before I bought the car and while I do have the old compressor and could get it rebuilt, I was thinking maybe this would be ok instead as I doubt they'll charge much for it.
 

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If the 79 has an ac delco A-6 ( long ) compressor on it , it will fit, but if it is the small radial A-4 comperssor it will not work with your freeon lines.
bewhere of wrecking yard compressors, it might need new seals, and other internal parts , but if its good run with it, look for wet oily spots or other damage

good luck
 

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Yup, they are the same compressor.

Only thing to look out for, the mounting brackets to the intake manifold are different, we ran into that problem mounting my stock compressor to the 472 intake manifold... family friend had some spare brackets he gave me... good to go and works like a dream :)
 

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'80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
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Look around the internet. Ebay and other places have these compressors cheap enough. Some are remanufractured. The pre '77 compressors have superheat switches and the '77 onward Cycling Clutch Orifice Tube system have low pressure switches. The Superheat switch makes a connection when the freon pressure is low. The switch on the newer compressors (I cannot remember the name for it) makes a connection when the pressure is over a certain level like 22 lbs or somewhere. The correct switch must be used on the C.C.O.T. system or it won't work as designed. It will kill the compressor dead if the charge gets low. The switch can be swapped by removing the snap ring. I'd rather just get one that is setup properly fom the start. Later compressors have about 2 different popular pulley diameters. Either will work fine but be ready to change the PS belt if you land up with one different than your original.
 

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Discussion Starter #6
Since the AC probably hasnt been working on this car for 20 years or so, Its going to have to be recharged, I was thinking Id take it to a shop to get it done as I know nothing about AC systems beyond the basics and I have no equipment for tackling such things. To change it over to "the new" system, is it just a matter of them putting in a new, different type of freon?
 

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to convert to R-134A the *correct* way is to replace the accumulator, purge the system pull a vaccum, make sure there are no leaks, then hit it with the same amount of R-134A as it called for R-12.

On my Oldsmobile, the AC was not working at all.... we pulled a vaccum, it held fine, then hit it with R-134A.... didn't change a thing, and it didn't blow up, imagine that.... yeah, you loose some cooling capacity, but I didn't care, only on the hottest days I would have to put it on max (recirc) and crank the fan speed up..... but for that car it wasn't a problem.

Probably end up doing the same thing on the '79 DeVille, my father pulled a vaccum, IIRC he said it is holding now that the main o-ring on the compressor is replaced.
 

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Er uh, why would one want to replace the accumulator in a C.C.O.T. system???
 
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