View Single Post
AaronM AaronM is offline
Ornery Bastard
 
Join Date: Sep 2001
Location: South Sound
Posts: 2,880
NO! Do not run the compressor while evacuating the system!

The Freon is also the carrying medium for the compressor lubricant, if the compressor runs with low Freon, it has a _very_ good chance of seizing. This is why the cars have a low-pressure cut-out sensor that shuts down the compressor if the pressure of Freon drops below a certain point.

The only way to get the R-12 out is to pull a vacuum on the system for a few hours. Furthermore, you _cannot_ just put R-134a in after evacuating the R-12. You need to replace the condensor (if you want adequate cooling, R-134a will use a larger condensor if available) and will definitely need to replace the receiver/drier as well as changing the compressor oil. THe oil that is used with Freon does not dissolve into R-134a and so is not carried through the system with R-134a. This means that just dumping 134a into an evacuated R-12 system will eventually result in compressor problems.

Take the car to a qualified shop unless you're just dumping R-12 into it.

Aaron
__________________
---------
Silver 1998 Volvo S70 T5 <- Daily (Anja)
Guards Red 1986 951 <- Seattle car (Gretchen)
White 1976 914 2.0 F.I. <- Prodigal car, traded away then brought back again (Lorelei)
Old 06-12-2005, 09:44 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)