A/C doesn't work. vacuum on low die. TXV expansion valve?

[91Beater]

When I got the car, the system was completely out of refrigerant. I was able to get it to accept the entire rated amount of CFC 12 after pulling a vacuum. When I pulled a vacuum, it held vacuum, so I don't think there is a massive leak.

It doesn't cool at all and after a few minutes, it will make clanging noise. I noticed that when I turn it on, it will immediately pull low side below 0psi into vacuum.

Since I know the system is properly charged, I'm guessing the TXV is stuck shut. The clattering must be from high side going through the roof. I need to check both sides, but currently, I don't have manifold gauge fittings for 3/16" high side port, so I can't do it.

Should I just replace the TXV, or do I need to replace the compressor too? I don't want to throw money at it, but then, compressor is expensive and so is R12.

[Legacy777]

Yeah it sounds like you've got a blockage or a stuck expansion valve. Honestly, I'd suggest retrofitting it to r134a unless you have cheap and readily available R12. Here's my write-up on it.
http://bbs.legacycentral.org/viewtopic.php?f=11&t=1083

I'm not sure if I've updated it, but the one thing I'd make sure you do is use PAG oil, the esther doesn't lubricate the compressor well enough and it will eventually die.

To determine where the blockage is, you may need to split the system in a few different spots to make sure you can blow air through. The condenser is a possibility, but probably not a big one unless the compressor died and through a bunch of junk into it. The expansion valve or the receiver drier is probably the more likely culprit.

Does the compressor spin smoothly if you spin the outer pulley? If you dump the compressor oil out of the compressor to look at it, check for metal flakes and other nastiness. If you see some, I'd say your compressor is probably on its way out and should be replaced. If this is the case, you should flush the AC system to make sure you've got all the contaminants out.