500E preventative A/C maintenance?

[tom woolner]

Is there any sort of preventative maintenance I can perform on my 92 500E? The A/C is about the only system I have not had to replace, and I would like to prevent that, if possible.
The only symptom I have had is occasionally blowing warm air for a few moments out the driver's side dash vent.
I run it at least three or four times weekly, as I prefer dry air, even when it's chilly outside.

Tom
92 500E
150,000 miles
new transmission today!

[y2kimmel]

Prayer is probably all you can do. the evaporator in my 1995 E420 went crappo on me about a month after i bought it in 2003. i spent the rest of the summer sweltering until the next spring - when my tax refund rescued me.

THe only thing that I could think of that may help is running the fan on high with the a/C off about 1-2 minutes before shutting off the car. WIll help get rid of condensation on the evaporator, which may help avoid corrosion. but then again, maybe not.

Troy
1995 E420 92k

Unlike most any other subsystem of any car, the refrigeration portion of the a/c system can actually have its life shortened by preventive maintenance beyond just keeping the fins clean on the condensor and seeing that there is a good and properly adjusted belt in place. The other thing you can do is occasionally put a thermometer in the vent and see that it is up to performance level by following the performance test in the MB service manual.

It is a bad practice to put gauges on the system as a preventive maintenance measure. Every time you do this or in any way crack open the system, you introduce the chance of allowing moisture to contaminate the system. Moisture combines with the refrigerant to form an acid that will eat up the components from the inside out.

As far as misbehaving vents are concerned, it is HIGHLY likely that the cause is a bad vacuum pod. There are about 6 or 8 under the dash that go bad with age. It is a significant job to remove the dash to replace them. If you were to remove the dash to replace one of them, it is HIGHLY recommended that you replace all of them. BTDT.

Good luck,

[gerryvz]

The best thing you can do for longevity is just to operate the system regularly. That means at least once a month in the dead of winter. Regular use helps preserve parts.

Cheers,
Gerry