Mercedes-Benz W201 air conditioning leak and cooling performance
W201 air conditioning leaks: where does the leak usually come from?
Most commonly from the seals and hoses, so frayed O-rings and the drier often need replacing. Sensitive points also include the compressor shaft, evaporator, condenser and connections. An evaporator leak drains out from under the wiper. The leak is located with a leak detector.
Why does the W201 air conditioning not cool or the compressor not engage?
The cause is often too little refrigerant. Then the compressor's magnetic clutch may not engage, and bubbles are visible in the drier's sight glass. If the compressor cycles on and off frequently, the pressure is too low. Have the pressures and refrigerant amount checked by an air conditioning service.
What is the normal vent temperature in a W201 air conditioning system?
At an outside temperature of 30 C, the vents should deliver air of about 10-11 C, and at 20 C outside about 6 C. The evaporator core temperature should be about +2...+4 C. The refrigerant (R12 or R134a) can be found from the sticker in the engine bay.