One turn seems like allot. If it gets too cold it will freeze the evaporator and reduce efficiency. Did it improve your vent temps?

__________________
1983 300D 280,000
1983 300TD 125,000 Killed by oak tree.
1983 240D Sold
1986 Ford F250 Diesel 6.9l 169,000

I think if there's enough air passing over the evap it might not freeze. I'll find out today and report.

edit: One turn CW had little affect. I pulled over and shorted the sw to make sure that it was the switch cutting off. Sure enough, my vent temps dropped to around 36f. I'll try another turn or so CW.

I have an '82 300Dt which was converted to r134a by PO. I feel it is in need of the stated adjustments at the evap temp switch and cutout switch. Where do I look for these jewels? I've seen some references but for us non-AC types it would be helpful with more direct language.

I notice on the expansion valve, there appears to be an adjustment screw with a "D" shaped ring for easier turning. Any gains to be had here?

I'm a total beginner with auto AC systems so pease excuse my ignorance.

Thanks
Sam

__________________
Best Regards,
Sam

'76 280 Time Capsule
'00 S430 Long Trips
'91 190E Seeing how far it will go. 366k
'04 American Eagle Motorcoach

The switch is located about a foot to the left of the expansion valve. It is a small box about 1x1.5" with two wires and a thin metal capillary tube coming off the right side going into the evap box.
I suspect, unless you added a PF condensor with the R134 conversion, adjusting this switch will offer you no gain.

I've been following this thread since it started, interested because my (new to me) 82 300D TD came with records that suggest the A/C (which wasn't working) hadn't actually been working for 12 years. The dealer referenced the need to recharge the A/C to the previous owner, and they said not to do it (go figure!).

Anyway, I took it to my trusted mechanic and he said, "let me pressure test it, and see what it looks like." I picked up the car later that day and was shocked to find the A/C runing perfectly (3-days later still is), and while I have not recorded the vent temps, I can tell you it borders on too cold (been 94-98 degrees the past week here in VA). It cost me $101. I was again shocked when he told me he recharged it with R134; I asked how that could be done as I imagined it was R12 in 1995 when last charged.

He told me, "that's just a myth, no problem at all!"

All of this seems to go against the recommendations of this thread where everyone seems to religiously change out the components, flush the system, etc.

All I can tell you is that it continues to blow cold air, and isn't leaking (did a blacklight test back at the shop this afternoon given he'd added dye for that purpose.

I'm no auto A/C expert; am I being lead astray here and looking at catastrophic consequences in the near future? I am enjoying the cool interior!

Simon

I'd be interested in what your mechanic did for $101. Purge, dryer, what type of oil??? You might want to start saving up for a new compressor.

I can assure you that a W123 AC with R134 will not cut it here in Texas this time of year.

Did Dave ever replace the evaporator on the 240D?