Need help recharging my A/C system.

I want to recharge my A/C on my 71 Barracuda. I have a can of R12 Freon and the system has never been converted to 134 so the r12 is correct. If I can find out which schrader valve to connect the can to - I can top this off in 15-20 minutes. I know I need to be on the low side of the system but "me is Stoopid"!! When I look at the compressor - there is a valve on the left head of the compressor- there is a valve on a small cylinder above the right side of the compressor - and there is a valve on the back side of the compressor that a hose comes off of and goes into the firewall. The hose then comes out the wall and goes to the condensor with the sight glass and onto the front of the car in front of the radiator before returning back to the compressor.

Which valve is the low side? I f you can help I would appreciate it.

Low pressure is the larger line high pressure the samller.

^^ true

You really need to add oil too. If your down on R12, your down on oil. Runing the compressor low on oil will soon lead to a sieze up and the whole system will be trashed with metalic debris from the crashed compressor.

Astrobuf