Digipixel

Been a while since I posted, but...

I'm planning on converting my 91 Civic A/C from R12 to R134A this weekend. When I hook up a pressure guage to the low pressure side of my A/C unit, it measures 0 PSI. Does this mean all of my R12 has leaked out?

My question really is this: Do I need to drain the lubricant oil out of the A/C compressor before I try to install the r134a refrigerant? If so, does anyone know where the compressor drain plug is to accomplish this?

The refrigerant cans say it includes a lubricant oil (and a sealer), but is this enough to replace whatever I drain out of the compressor?

Thanks....

Digipixel

I think I may have answered my own question - after further research I discovered that the r134a refrigerant includes ester oil as a lubricant. Turns out that ester oil is compatible with the lubricants (mineral oil) used with the old r12 refrigerant. Looks like I don't need to drain the compressor after all. Whew....

nando415

i think u need to retrofit the ac system before you put r-134 freon in the system, let me know what you did and how it worked out