A/C pressure 850 GLE 1996 + new refrigerant

Hi folks, my refrigerant leaks (very slowly - takes about 2 + years to
leak out). So when this years AC produced no cooling I decided to DIY
refill.

My A/C was dealer retrofitted to 134, and I found a refrigerant at
canadian tire called Red Tek. It's compatible with existing system,
and apparently environmentally friendly (14$ per can, or 49$ as kit: 2
cans and hose/pressure gage).

Although my AC was not cooling prior to refill, the pressure in the
system (with engine off) was 40. I added one 6 oz can of red tek with
engine on and ac on. Now with engine off pressure reads 65. With
engine on and AC on pressure runs at 40, and down to 25 when
compressor kicks in. When I turn off the car pressure reads 65.

AC cools very nicely.

Is the pressure within norm? If not - what should I do?

Thanks! Mark

 

Firstly these DIY refills are IMHO a waste of money, as proper ac
performance is very much dependant on exactly the right charge, which is
done by weight. You have no idea of how much R134a is in the system from
reading the low side alone.

25psi is somewhat low anyhow even if you were reading the high side, which
incidentally is only possible with a scan tool connected to the car- there
is no HP side port on these cars.

Secondly the 850 was never anything but R134a, so 'retrofitting' it was
never an option.

Tim..

 

Does the 850 system use a TXV or a fixed orifice? The charge is much
more critical in the latter.

DIY is pretty easy if you start out from empty. You have to have a
vacuum pump to do this, but you don't need a particularly good vacuum if
the system has not been completely up to air. If it leaks out in 2 years
though there's a problem somewhere. I retrofitted and charged the AC in
my 740 about 6 years ago and it still works great.