A tale of two A/C conversions - Page 2 - PeachParts Mercedes-Benz Forum

tilac1 · #16 07-16-2013, 05:00 PM

Good idea, will pinch off the hose going to the heater core as a test. I've converted other cars to 134a and had fine results. This one is strange.

Quote:

Originally Posted by nelbur

I wonder if your heater core is getting some hot water through a leaky shut off valve. 134a is not the problem. I have converted two R-12 systems to 134a, and had trouble with one system freezing ice in the evaporator, so 134a can put out cold air.

tilac1 · #17 07-19-2013, 05:30 PM

I had poor performance from 134 despite all new components. I figured I'd try Enviro-Safe so I tried the industrial version.

Evacuated, flushed and pulled a vacuum. Followed the directions to the letter. No joy. Compressor engaged, low side pressure 25psi, no cool air, 95F ambient, 40% humidity. Added another 6oz can just for the hell of it, 45psi low side, no cool air coming out of vents. Heater is not part of the problem, I pinched it off to be sure.

I don't have high side pressures figures. Something blocked like the TXV?

slk230red · #18 07-20-2013, 11:15 AM

You really need to post low and high pressures. Maybe something clogged the expansion valve.

tilac1 · #19 07-21-2013, 07:18 AM

I think that may be it. I went back to 134. I've got cold air coming out of the vents now but nowhere near as cold as it needs to be on a hot day.

Quote:

Originally Posted by slk230red

You really need to post low and high pressures. Maybe something clogged the expansion valve.

strelnik · #20 07-21-2013, 07:27 AM

Quote:

Originally Posted by tilac1

DIY R134 conversion.

1. 1988 W124 300E, new compressor, receiver drier, expansion valve, all O rings. Converted to R134. Fully charged, no leaks. Low side, 55psi @ 90F ambient. Vent temps only 66F

2. 1987 Peugeot 505, converted to R134 last year, Ambient 90F, vent temps 46F

How can I improve the Benz's temps without going to R12?

I have an unrelated question: where did you get the Peugeot 505? where do you live?

tilac1 · #21 07-21-2013, 07:49 AM

Quote:

Originally Posted by strelnik

I have an unrelated question: where did you get the Peugeot 505? where do you live?

Massachusetts. I found it on CL w/60k miles. It's a 1987 Liberte wagon and it's the 3rd Peugeot wagon I've owned. I love it.

tilac1 · #22 07-21-2013, 07:52 AM

All I did to the Peugeot is change the fittings to 134 and juice it up. That was three years ago. Blows cold. Can't understand how the W124 system is much different.