A/C saga - '78 300D (still NOT very cold)

[rgnprof]

I am going to try and summarize what I have done up to this point. When I got the car - no A/C, no gas at all. I have replaced the suction hose (compressor to evaporator) and the hose from the compressor to condensor, new drier, new belt (and tightened), new expansion valve, new pressure switch and new temp switch (both located on the drier) and new aux fan. This has been done in stages (some of you will recall my previous posts). Yesterday, I had my mechanic evac and vacuum the system as we decided to replace the expansion valve as the old one was leaking. Recharged with R12 - the best he could get the low pressure was about 20 and the high pressure was up to 225 - with car running at approx 2000 rpm and ambient temperature in the upper 70's, maybe 80 degrees.

This car has the York compressor and the ACC servo.

Vent temps are still around 60 - dropping to mid 50's (which would be less than a 30 degree difference from ambient to AC air). The auxiliary fan is now working properly since I have installed a new 52 degree C temp switch in the drier (fan runs when I ground the wire leading to the thermostat housing sensor and when I ground the temp switch wires together at the drier). Yesterday, the fan did not come on at all, even as the car sat at idle. At idle, the compressor cycled on for approx 45 seconds, then off for 12-14 seconds - with ambient temps in the upper 70's.

The car cools better at idle than it did, but I am still disappointed in the performance. Any other TS suggestions? I have noticed than when I turn the system to Auto HI, some air is blowing out the defrost vents, so I'm wondering if I could have a vacuum related problem and that I'm still mixing too much warm outside air with cooled air??

Or could I just have a tired compressor - I have noticed that the clutch doesn't seem to rotate as fast as it should at higher rpms??

I'm just at a loss...

Ryan