R134 pressure/refill

beartracks · #1 (**permalink**) 05-01-2007, 10:48 AM

My system was converted to R134 10 years ago but doesn't cool as well as it used to. What kind of pressures should I look for?

How about the refill cans with leak stop in them? Bad idea? Oil?

Rusty_S · #2 (**permalink**) 05-01-2007, 11:44 PM

Heres are the pressures for normal functioning systems

these are all at 90* Ambient Temp.

High Side Pressure :
200 - 310 psi
Low Side Pressure :
(STV, POA, or VIR systems) 28 to 31 psi
(Expansion valve Systems ) 7 to 15 psi
(Orifice Tube Systems ) 24 to 32 psi

The leak fill will work for small leaks but if its a fairly large leak its a waste. Plus I have seen in some instances where it fouls up the a/c compressior.

For oil, you only add oil when oil comes out of it. But if you dont know how much oil was in there to begin with you could add half of the recomended to be safe.

kermmydog · #3 (**permalink**) 05-06-2007, 01:26 AM

If it has been 10 years since it has been serviced you should replace the filter/drier & pull a vacuum and recharge. If you ever put in anything like stop leak it maybe impossible to find a shop to work on it. That stop leak messes up their recovery systems and most shops check to see if there is any in the system with a special meter.
I'm ASE certified on A/C systems along with I hold a Type I & II EPA cert also.