duo valve w140

[sully]

1995 w140 s500. Wasnt getting any heat blowing in the cabin, so i followed the guide on here about how to strip the valve (very helpgul by the way). I have 2 questions now -
1. At each valve there was a pipe leading into the bulkhead - im thinking to the cabin for heat etc, but inbetween these 2 pipes, there was a third exit, but this was blocked off. I couldnt find a pipe that would go to this exit. Is this right or has some1 blocked this exit off??
2. Whe i had stripped the valves down, i found that the brass valve that moves up and down were actually snapped off at different lenghts for some reason. Are these parts avilable seperatly or do i haveto replace the whole duo valve??
cheers for any help

 

[wscheffer]

It sound as if the PO had blocked off the return pipe that goes into the top of the block. Probably the valve became faulty during summer and was stuck open. So they blocked it off, a quick fix till you get around to repairing it.

 

[42864]

Sully , sound as if the Duo Valve is knackered, best advise is to try and source one from a scrap yard and either fit that or make up one good one from the two. A new Duo Valve from Mercedes will cost in excess of 200-00pounds

 

[sully]

so the blocked pipe should go to the block then?? Ive only owned the car 6 weeks and i got it cheap enough, suppose this is why.
Already priced one from the merc stealers - £318 +vat!!
Will have to try get one 2moro from breakers - oh joy!

 

[television]

so the blocked pipe should go to the block then?? Ive only owned the car 6 weeks and i got it cheap enough, suppose this is why.
Already priced one from the merc stealers - £318 +vat!!
Will have to try get one 2moro from breakers - oh joy!

I wonder where MB get their prices from for some of these parts

There other firms that sell them, try GSF or Euro and that bba reman

 

[Parrot of Doom]

Is the duovalve the same as other Mercedes cars? If so, look around on Ebay for similar cars being broken.

 

[42864]

Is the duovalve the same as other Mercedes cars? If so, look around on Ebay for similar cars being broken.

I think that you will find that this Duo Valve is only fitted to the L W Base cars. When mine went I was quoted a similar price and upon checking found that this Valve is a special, apparently it is because of the rear seat heating system.

Might be worth giving Mercman a call 023 8078 4444.