I seem to remember a thread about stripping down the AC pressure regulator assembly, which is located on the chassis next to the engine, and which the tiny pipe from the TX valve is connected to. But I cannot find that thread, unless it was in my imagination! My problem is that the suction pipe between the compressor and the pressure regulator is icing up, which must be bad for the compressor, and which also causes heavy condensation in the evaporator area and consequent mould build up. I had my system completely overhauled a couple of years ago, new compressor etc, and the system was flushed and refilled with R134 gas instead of the original R12 (this was a requirement of the new compressor in order not to void the warranty, and anyway I didn't want to use R12 if it could be avoided). But I think the new gas may now have caused the failure of the pressure regulator. I'd appreciate anyone's advice on this, and if anyone knows what one of those valves costs new please let me know. I'll make sure I'm sitting down before I read the reply! Oh, and before someone shouts at me, I do not intend to work on a pressurised system by myself! There's a guy locally who can evacuate the system and regas but he needs me to research some of the specific peculiarities of Soarers - not many specialist AC places in my part of the world, the nearest to me is probably 400 kilometres away.
I found the thread I was looking for - called "Do regulators leak?" and dates back to last year. Someone there was saying that putting R134 gas into a system originally designed for R12 would cause the rubber seal in the regulator to fail. I know the 2 gases are incompatible, but I wonder then how people convert their systems from R12? The Soarer manual, originally made for the USA, says that the system uses R134 (perhaps that was a requirement for the USA) so presumably their regulators are good for conversions.