Re: R 134 not too cold?

This is a little off topic, but here goes.

I heard that these suburbans with rear air have pretty efficient cooling systems to the point that if it's run without a heavy heat load, the compressor will receive refridgerant that is still liquid causing premature compressor failure. I guess trying to compress a liquid doesn't work. The recomendation was to always run the rear A/C system on Hi when A/C was running.

Is there any validity to that?

Jason

There is no validity to that at all. The Suburban, even the earlier models have always used an expansion valve located near the rear evaporator. I have seen expansion valves fail (blocked) by debris from somewhere else in the system, but never catastrophically to the point were it would destroy the front components.

Rita

No, as others have said. I believe what you are hearing is a fifth hand retelling of a story. The only issue I know of is that the rear coil will freeze up if the rear fan is on the lowest setting. It doesn't happen often up north or out west, but down here in the humidity belt I know of a couple people that have this problem. Adjusting the amount of freon or (preferably) not using the low position on the rear fan solves it.

It's very well known that an R12 auto AC system converted to 134a will not be as cold as it was with the R12 coolant..

That's because the system was originally designed to work with the R12 Freon refrigerant not 134a.. R12 & 134a have different evaporation (or liquid to gas) characteristics.. The mechanical components (Compressor, condenser, accumulator etc,,,, were designed to work with R12...

Slyder..

Hes right on that, my 88K5blazer is changed to 134-a and it does not get real cold on a hot day but it does keep me comfy.

P.S. The dupont co. was responsile for the outlawing of r-12, and they had all the new stuff ready too sell. Danger to the ozone BULL. What does all the space shots do to it? Nothing is ever said about that.