I'm about to replace the evaporator and expansion valve (as well as the compressor and receiver) when I change the system back to r12 from 134a. I already have the expansion valve, receiver and compressor, but waiting on the evap and I have a few questions:
1) My parts references show 1990 as having an externally equalized exp valve. I think I might have the wrong valve because the new one is not externally equalized. Is it just a different type of valve that doesn't need the extra tube, or is there some advantage in the external tube?
2) If the new evaporator comes with a fitting for the extra connection should I insist on an externally equalized valve, or cap the fitting and move on?
3) A small sticker on the expansion valve says "hfc r-134a" on it but the a/c parts house insists it is the right valve (I am putting r12 back in the system). Does this mean it is calibrated for 134 or does it just mean that the sensing bulb contains 134?
Thanks in advance,
[ September 07, 2005, 09:09 AM: Message edited by: Walter McNeil ]