For backround purposes, 1979 Datsun 280zx NA A/C from the factory, don't know if it's been converted or not but going by the fittings, no. The question is this, since I've had the car the compressor has been locked up and unturnable by hand . I assumed that being so old it finally gave out and froze, today I decided that I can do without a/c since I don't want to pay for a new compressor and started removing the dead weight. I got some lines off, the condensor, the accumulator, etc and when I came to the compressor I grabbed it for leverage and realized that the clutch would turn by hand. Without the compressor under pressure it turns smoothly and easily.

Does anyone know if this means that it's actually good? Or does it just turn because there is no pressure in the system, could too much or too little R12 have caused it to freeze up? I'd just like to know if the a/c system is still good or trash because I'd hate to get rid of this stuff if all I need is a retrofit kit but, I'd also hate to go out and buy the stuff only to have it freeze up again under pressure.

 

Are you sure it's the clutch thats spinning and not just the pulley? Because the clutch isn't supposed to turn unless it's energized. If you turned it by hand and the clutch turned without power being supplied then you've got a bad clutch.

Generally the way compressors go bad is one of two ways: One is lack of lubrication. If the system gets blocked up or is really low on refrigerant this can happen. The other way is if the pressure gets too high and the compressor can actually damage itself (bend a valve, etc...). Of course with time parts, like bearings, do just tend to wear out

 

Hmm I don't know if it helps but the pulley and clutch spin individually, the pulley spins freely and the clutch spins smooth but with obvious resistance from internals.

 

DO NOT GET A 134a CONVERSION! Cheap, synthetic, legal R-12 substitutes are currently available and they work about 10 times better than 134a systems.

 

A fellow R12(ish) advocate

 

I didn't know lol

So, is this worth saving or what? Im kind of in the middle of removing all the stuff but, if it's good I might as well put things back on, or maybe just leave it off for awhile I dunno, it's mixed thing

 

It's up to you really. If the compressor isn't actually seized like you originally thought it was and everything is functional then all's you'd really have to do at this point is replace the receiver/drier and have the system serviced. Once the system has been opened you cant just put refrigerant back in it. And once the R/D is exposed it can't be reused in most cases either. Those are fairly cheap though.

 

Well it's getting dark and I already have most of the stuff is already off so I went ahead and finished taking off the rest, I'll save the stuff in case I change my mind. Thanks for all the help guys.

 

seal everything up otherwise it'll all start corroding from the inside out.

 

Sweet that's what I was hoping for. lol, I'll take care of that tomorrow.

 

OK, does the center of the compressor pulley The compressor is junk, period. Now if you want to put AC back on you need to take it to a shop that does lots of AC work and have them flush the entire system, replace the Drier, orifice tube and anything else (like accumulator or whatever under the dash) that will hold crap, and a new compressor and it will be good for years. Sounds like the old one puked garbage into the system, is there junk in the lines? some kinda dark ooze.

 

Not sure if that makes much sense but the rest was good advice

 

Everything that came out was kind of a clear blue color.

 

I was trying to ask if the center of the compressor pulley (the compressor shaft itself) turned at all or just the outer pulley.