71 Green 454

Do the R12 to R134a adapters require the removal of the old schrader valves on the GM A6 compressor?

'75

It depends on the adapter used, most I have seen keep the schrader valve in place. The 90 deg adapters have a schrader in them so the original needs removed.

toobroketoretire

I modified my R-134 refrigerant can adapter so I can charge my system thru my R-12 gauge set. So all of my fittings remain R-12 but I'm running R-134. I guess I'm just cheap?

mrvette

Same thing here, but to charge a 134 car/wife's car, I had to cut a couple hoses and then splice/clamp them together as a miss match to get the correct end.....my gauges are probably 30 years old.....pressure is pressure, but I HATE 134, wish 12 would come back...leaks less....stupid EPA.....

71 Green 454

I can do the same thing, but I'm just wanting to be legal.

zwede

It's been a long time since I did mine, but I remember the large adapter didn't have a valve (old one was re-used). The smaller one had a valve and the old one had to be removed.

Bandel

Is R134a a direct replacement? I thought you'd have to change the expansion valve and o-rings?

zwede

A correct conversion includes new o-rings, adjust the POA valve (or replace orifice tube on later C3s), and a parallel flow condenser. And the adapter fittings, of course.

If all the above is done the R134a system will blow as cold as R12.