I never did have working dash air, so when we had to do a water pump replacement on the road the compressor went in the basement, then the warehouse when we got home. If one was to go way back, we discussed thermal insulation of the doghouse, I did inside and out, and REAL good weatherstripping around the hatch. You get 2 benefits, engine heat and sound, which makes it well worth while. On the rare occasion when we really need air, the Onan uses less than 1 GPH, and the roof air actually cools the entire coach, not to mention those in the back can watch a tape on the tube if they wish. If I had a new, high end coach, I'd probably be a little more concerned, but for what I've got, and what we do with it, I'm not spending any money to get that little hang-on aftermarket dash unit working.

I had three vehicles converted to R-134a, my '87 E350 van, my '89 SOB, and my '91 Mazda 929S. All worked fine.

It takes about 2.25-2.5 lbs to charge my 28' Breakaway.

quote:

I've been told that the reason is that the condenser used for R-12 is not large enough for R-134 and to get close to the R-12 cooling, a larger condenser would have to be installed, assuming you have room for it.

R-134a ia slighly less efficient at heat transfer than R-12, and is more sensitive to pressures than R-12. The cooling difference is really quite small.

The hydrocarbons are slightly more effiecent than R12. Also the larger molecule is more resistant to leakage. Works well in our Barth

I have a GM service bulletin on retrofitting R-12 vehicles R-134a.

Any supporting member can have a copy.