124 (1990 300E) A/C woes. - PeachParts Mercedes-Benz Forum

cjlipps · #1 07-05-2007, 04:26 PM

I'll try to keep this brief because there are too many a/c threads already. I just have info that is unique to my vehicle and am looking for help in a diagnosis and repair.
My car had been converted to R134 at some point prior to my owning it. Current mileage is 161K. Mileage at conversion is unknown and whether compressor was changed at that time is also unknown. I checked the pressures in the system and they were in the neighborhood of 280/45 with an ambient temp of 80 and with the car at idle. Vent temp was 60ish at that time. All fans are operating fine (new clutch recently) and car does not run hot. (Radiator has been removed and flushed and condenser washed at that time.) On the highway with outside temp at 75 the vent temp will not go below 50. In the afternoon with OAT at 90 for the return trip, the vent temp won't go below 60. The sight glass shows foaming and the refrigerant is day-glo flourescent green and oily. I pinched the hose to the heater and it made no difference so I don't suspect the mono valve.
What are normal pressures? What is the green crap? Should there be bubbles in the sight glass or should it be clear like the old American stuff I'm used to working on? If I were to evacuate and refill with R134 what is the proper amount to install? Would a conversion back to R12 be wise?
Please post or PM if there is anything I left out that would aid in a diagnosis. Any help is appreciated. I think the monsoon season is over here and normal triple-digit temperatures are on the way.
Chuck.

Sorry, got this in the wrong place. Can you move it for me? Thank you.

cjlipps · #2 07-07-2007, 09:43 AM

Sorry again about the wrong location. Anal insertion of the cranium. Can we move this thread so I can get some help?
Thanks, Chuck.

cjlipps · #3 07-09-2007, 01:06 PM

bump again.