AC Vacuum Pump and Oil

[Dynomite]

Originally Posted by VetteVet

Cliff,

Vacuum for an hour, then shut gauge manifold valves, turn off vacuum pump and monitor vacuum in system for evidence of any leaks. If none, you're set to charge with the amount of R-12 listed in the FSM. When you connect the can, make sure that you have the can upright and then loosen the fill hose at the manifold to purge the air, then retighten it. The can has to be upright to ensure that you get vapor, not liquid. Charge to the low(suction) side with can inverted until you cannot get any more Freon to flow into the system, then return can to upright position, start engine, leave doors open, switch climate control to auto and set to lowest temp setting. If you don't have enough pressure in the system for the A/c compressor to kick on, disconnect the pressure cycling switch and jump the two wires to energize the clutch. Add remaining Freon to the low side with can in upright position. You don't want any liquid Freon hitting the compressor, as that will damage it. Remember to shut the low side valve when changing cans and also re-purge the fill line. It doesn't take very much air/moisture in the system to seriously degrade performance.

The FSM lays it out very nicely. Shoot me a PM if you have any questions.

Jep

Jep:
Thank you thank you
I will think, study, and think some more and maybe PM you if I have questions......I am not sure about the oil yet but did not loose very much oil as my understanding most of the oil resides in the compressor. I will give it a try....and thanks again.

I am sure anyone who has pulled an LT5 moving the AC compressor out of the way over to the drivers side has prolly done what I did once or twice....pulled too much on the AC line attached to the evaporator

Cliff