Philoprof

A friend of mine was having trouble with the AC on his 2002 C240 blowing hot air, evidently because the freon was low. So I added two cans of dye charge, which brought the low side up to 40PSI and caused the AC to work properly.

A couple of weeks later, however, the AC started blowing hot again, even though the low side pressure is 30-35 PSI. But I can't detect any leak.
Should I suspect the evaporator, or is there something else to check first.

I understand that the C240 has AC codes, but I don't know how to pull them. So any help would be appreciated.

Thanks in advance

Glyn M Ruck

You need a STAR to pull AC codes. Does the pump start? The pump won't start/switch on if the Refrigerant is low. It could be pipework, condenser or evapourator

Philoprof

Thanks, Glyn. Unfortunately, I had an Indy who specializes in AC add dye charge to the system, and he detected the dye and freon coming from the AC drains under the car. So, he's 100% certain the evaporator is leaking.

Unless someone here can think of some other reason for this, my friend's going to have this Indy replace the evaporator for $1000 in labor, and we're going to get a Behr evaporator on-line for $335 delivered. Does anybody happen to know who made the evaporators MB put in these cars? Hopefully it wasn't Behr. In any case, the best price we got from a dealer was around $2000 ($1500 for the labor (15 hrs @ $110) + 800 for the evaporator - 15% because of the AC special their running).

Based on an archive search, I' m assuming we should also replace one or more plastic stepper motor links and/ or stepper motors, but i'm not really sure which ones. Are any of these more prone to breaking than others?

I was also wondering if we should go ahead and replace the heater core while we were in there, even though I didn't find any reports of heater core problems in W203's?

Any additional advice would be greatly appreciated.