[V6-12v] DIY A/C recharge, stop-leak treatment

[Tom Christiansen]

Folks,

Replaced my A/C compressor myself two weeks ago. Took the car to the 
A/C shop this morning to have the system recharged. Just heard back 
from the shop. The system pumps down to vacuum fine, but once the 
vacuum pump is shut off, it doesn't hold vacuum. There's a slow leak 
somewhere. I had the shop pump some refrigerant with dye into the 
system. Hopefully that'll leave some trace where the leak is.

Have any of you tried recharging your A/C yourself? Any luck with it?

Some people say you have to recharge from the high pressure side. Is 
this true? Would the high pressure port be the one on the condenser 
(in front of the radiator)? How are the R134 "spray cans" set up for this?

Has anyone used some sort of stop-leak treatment for the A/C system? 
Did it work?

Tom