My dealer told me that I need to replace my "dual valve" on my '93 500SEL.

Hi, I am new. Name is BudW. Yeah, that W is for Wiser. Says so on my Visa cards.

So can my old, not working at all "Dual Valve" get reincarnated?

What about used "Dual Valves"? Who might sell these things?

Thanks all.

Pics later, I promise. Black is back!

BudW

hi budw, sorry to hear about your dualvalve. read this thread from the w210 forum, somewhere in the first page they describe in detail how to clean the dualvalve, maybe yours needs just a cleaning. hope this helps.

http://www.benzworld.org/forums/w210...-cold-air.html

Thank you.

Your reference was very helpful.

Especially, helping me understand that I need a duo valve and not a dualvalve.

Oh my, age is catching up to me too fast.

BudW

Here is a rebuild of the rear climate control duovalve. The front climate control is very similar.

http://v12uberalles.com/Rear_AC_System.htm

Brett

Brett, I am IMPRESSED. Alas, I must admit to be a clutz when it comes to such detail but I have been inspired to see if I can actually do a remove and replace using a used duovalve from Potomac German Auto. They sell my duovalve for $239. If I do manage to install it (front heater controls) then I avoid the $900 the local Mercedes dealer wants for the job.

Thanks again. Without your help, I would be out $900 for sure.

BudW

$239 for the duovalve is pretty good. those little *******s are expensive, i think new they are like $500.

The duovalve rebuild is not my work. That is the site owner's (Pete, pcmaher) own work. I've just contributed some articles on some work that I've done on my own S600.

Brett

Very nice write up. I have 99 s420 that is not producing heat. I check the duo-value motor with a batter and I can hear it run. I check each of the duo-value circuits and I can hear them actuate. I checked the fuse and they are good. Still no heat. What else should I check?

hmm i need to check mine, jsut posted about this issue too

I remember when my DUO VALVE gave out, I said THATS IT. Sold her and never looked back.
I couldn't believe a 100k dollar car could fall apart so fast.

Designers must have had manure for brain. 1 billion spent in developing a car whose climate control hardly ever works,window regulators give out.


Lesson learned, never buy a German car....LEASE!!! MB has abandoned the idea of building long lasting cars a while ago. Now they are into making 2000HP tire burners that last the duration of the lease.


Good luck with fix!