A/c Stopped working in VERY hot weather

[kengriffith]

W210 98 AC compressor recently replaced. AC working well for last three months.

Yesterday in very hot weather (110 degrees) on freeway, AC stopped blowing cold air. I turned it to off and rode with the windows open for a while. When I got off the freeway, I turned it back on (still 105 on the dash). Both aux fans were running full blast(engine temp by the way was fine), but still blowing warm air. I noticed that the system seemed to vent a bit of gas(very quick, like an overflow valve or something(seemed that the system was over pressureized and needed to let off some pressure. Turned it off again.

Later that evening in 95 degree weather, I turned it back on and it ran fine for the hour drive back to my house.



Can anyone shed some light on why the system shut down? Got overheated etc?

KG

[Matt L]

There is a relief valve on the rear of the compressor, which is not supposed to release refrigerant. Perhaps there is a restriction in the high side of your system. The condenser and dryer are before the pressure sending unit, so if either of these are restricted, the CC control unit will not know the true head pressure and the relief valve can pop.

My car suffered from a plugged dryer. There's a TSB on it, but I do not know if it applies to a '98.