hey guys, i have an 89 trans am (305 tpi) and I am about to add some r-12 and i just want to make sure which is the low pressure side? Both fittings are the same size unlike r134 systems, and I don't want to have any problems.. thanks

 

the low side is on the accumulator

 

thanks man

 

woah where did u get the R12 from and how much did it cost???

 

i found a local guy selling 2 cans of it for 20 bucks each on craigslist so i snatched em asap! i do have a new problem now though.. as we were adding the r-12 (the compressor kept engaging and disengaging) ..the compressor started staying engaged a few seconds longer than normal and then the compressor started to smoke slightly so I shut the car off right away.. my dad said that it looked like maybe the ac clutch was getting stuck or something (he also said it sounded like it was rattling) … sooo anyone know if my compressor is bad or just my ac clutch?

 

Dude that sucks. Your compressors seized. Sometimes happens when a system becomes saturated with moisture or just old... You need info on a retro fit let me know. be sure now when you do everything (compressor) Replace the accumulator, orifice filter, flush the system than install everything. Good luck

 

When the system has only a little pressure (~15 psi) the compressor will engage, and then dis-engage often as the low pressure enable switch opens and then closes. This is normal and caused by the pressure change as the compressor pumps up.

The temporary solution is to disconnect the low pressure wire plug from the switch, and then short across the two pins with a paper clip, this will make the compressor run the whole time. While doing this add more freon! Soon there will be enough pressure to allow the system to run the compressor continuously without the paper clip jumper in place. Reconnect the wire plug to test.

Top it off with about 35-40 psi while running.