A/C o-rings

[SumDude]

Im looking for an o-ring kit for a 92 525i that has had the factory retrofit done from R12 to R134a. I can't seem to find any R134a o-rings for the E34. Also i know it was a R134a compressor but it still has a R12 Condensor, should i think about changing it and if so, where do i get a R134a one to fit

[Ross]

No need to change the condensor.
The R134 molecule is smaller I'm told so finds leaks easier and the pag oil is different from that used in the old R12 systems and is supposed to effect the rubber over time.
I've changed some of my own systems and left the O-rings and seals in place with no discernable leaks. Maybe they are coming but the labor to disassemble every joint to change an O-ring that might leak is too much for me to do until necessary. Given the age of our cars you need to examine wether it's worth making a system to last forever.

[Blitzkrieg Bob]

I just change the dryer, add a recharge with dye and watch for leaks.

The old sysytem will hold up if its in good shape.

[winfred]

the way i convert any car is, pull the compressor and drain the oil out of it and add 5-6 oz of ester oil, change the drier, change the expansion valve and while everything is apart i blow the old oil from the evaporator and condenser with compressed air, put everything together with the green o-rings (hnbr) and put a drop or two of the ac oil on the o-rings before you install them, once everything is together and vacuumed down and you have put the first can of freon in, turn the compressor over several times by hand before you start the car to clear the oil and freon out of the cylinders, the system takes 3.4 pounds of r134 16 oz to a pound 12 oz in a can,

ps, make sure that the electric fan is working, it should come on low with the ac and when pressures get high enough it will shift to high, if it doesn't come on with the ac the resistor is probably blown, the fan will blow the fuse after a short while if the resistor is bad as forcing it to start in high overloads the fuse

pps, i don't like pag oil in conversions as it can react with the copper in older systems

[Guapo]

Check ackits.com for an o-ring kit. They have a set for euro cars that had all of the necessary o-rings in my conversion.