Quote:
Originally Posted by jbaj007
Straight propane has pressures that are WAY too high for MVAC use. The P/T curve for propane is almost exactly that of R22, not R12. It's use in Mexico would add more excitement to an already exciting driving experience there  .
The addition of ~30-40% isobutane to propane puts the thermodynamics more in the R12 range.
I AM NOT ADVOCATING THIS. I have used a "test" refrigerant when I had a particularly difficult leak to find (it was leaking thru the WIRES of the aux fan switch as it turned out!!) and found it performed nicely; very much like R12; not better, but like R12 IMHO.
Your symptoms (would REALLY help to have pressures, ambient, RPM, but.....) are classic for lack of heat exchange at the CONDENSOR. I know you say the fans are perfect, but the rain scenario says otherwise. Low charge will do the same.
Why are you replacing those parts on an operating system? Leak? compressor noise? |
The reason I'm rebuilding the system with new comp., exp. valve, and drier is;
1. I am not certain whether or nor it is charged with R12 right now, therefore, I don't know what the gauge pressure should be.
2. Assuming that it has R12 in it, low side is bet. 15-20 psi and high side is bet. 200-220 psi @ 1500 RPM and it gets cold, but not when at idle around 700 RPM, as if the CCU control is set to ECONO.
3. Assuming it has 134a in it, manifold pressure is still off specs.
and by the way, here's another twist:
4. There is an R-134a retrofit sticker under the hood but there is neither high nor low side retrofit quich connect fittings, just the standard R12 fittings.
....hence the reason I wanted to overhaul the system by changing the compressor, expansion valve, and drier so I can start from scratch myself and won't have to chase the PO's previous AC work.