Which is low side ac nipple?
 

I checked the ac threads but couldn't find the answer to this.
Which is the low side nipple? The one on the passenger side firewall or the one next to the can up front?

The one on the passenger side is the low side in my `86. The high side is a differant size and the charging kits you buy at the autoparts stores will not fit on the hi, only on the low. They do that so you don`t get a face full of shrapnel by blowing one of thoses small cans of refrigerant up. If you need to do anything with the hi pressure side either take it to a shop or find an individual that is qualified to service the system. You can get an adapter to fit the hi side which you can then attach a set of manifold guages to so the system can be flushed, evacuated etc.

Low side in A/C lines is usually the THICKER/ BIGGER line.

Don't know exactly for the FC, but most cars are this way.

Yeah low pressure side is the biggest fattest nipple. I recharged my system with r134a but the leak i have is so big it left the system ASAP. So i think ican still put r12.

Jason NYC

A leak is a leak if its large enough to leak down fast then find it and fix it before adding any refrigerant. It will leak out no matter what refrigerant you use.
R12 is CRAZY expensive like gold, if you are going to waste it just send it to me.

I didnt know it had a leak, i stole a recharge system from autozone when i worked there just to see whats up. It was good for half a day then it was gone. But i will find the leak first and fix it before i put in R12, DUH!!!!!!!

Jason NYC