That's another thing I'm wondering about. I'm always a bit concerned about putting things back the way they came apart -- if they had previously been taken apart and put together by someone else who didn't know what they were doing. Maybe two years isn't unusual failure for this part but I think it's premature, which makes me wonder if it was installed incorrectly or something, although from what I can tell, it would be hard to install it incorrectly, unless that wavy washer can be put in the wrong place (or left off entirely). As far as I can tell, the first one lasted 30 years, but who knows...maybe they just break a lot. They are certainly sold everywhere, that's for sure. Any difference in brands? Maybe I should buy a $40 Indian Bosch vs $26 Chinese alt brand.
Jim
--- In
diesel_mercedes@yahoogroups.com, BStromsoe
<bstromsoe@...> wrote:
>
> Only if the previous installer was not paying attention and did a lousy job. Pop it open (4 screws and 5 minutes) and look.
>
> Â
> brian from la verne, ca
>
>
> ________________________________
> From: n61cm
<jim@...> > To:
diesel_mercedes@yahoogroups.com > Sent: Thursday, October 6, 2011 7:50 AM
> Subject: [diesel_mercedes] Re: Monovalve repair 84 300D
>
>
> Â
> Thanks for the info. But do the guts of these valves ever get corroded so much that a new valve won't seat properly and thus allow coolant to leak through continuously?
>
> Jim
>
> --- In
diesel_mercedes@yahoogroups.com, audiolaw@ wrote:
> >
> > Jim,
> >
> > Monovalves are among the easiest service tasks that you can do. The
> > valve is easy to find and work on on the 123 (much easier than on the 126).
> >
> > You can either replace just the active part, by removing the four
> > screws on the top of the valve body and lifting it out (remember to unplug it
> > first. Then drop a 'new' one in, reinstall the screws, connect the plug and
> > you're good to go.
> >
> > Or you can pull the whole thing by unplugging, then disconnecting the
> > water hoses, then dismounting. Install the 'new' one.
> >
> > I say 'new' instead of new, because these are easily pulled from cars
> > in P-a-P yards. You can open the valve up (remove the four screws) and see
> > if the rubber is OK, and see if the channels look clean or clogged.
> > CHEAP, CHEAP, CHEAP. And good exercise walking the yard.
> >
> >
> >
> >
> > In a message dated 10/6/2011 7:01:58 A.M. Pacific Daylight Time,
> > jim@ writes:
> >
> >
> >
> >
> > Howdy, the monovalve on my 84 300D lets coolant through all the time, never
> > completely shuts it off, raises the air temp 10 - 15 degrees at its
> > coldest setting when it should be shut off. The valve was replaced a couple years
> > ago by a Mercedes shop. Seems too soon for it to have gone bad, but who
> > knows.... I see that those valves have rubber washers or o-rings or whatever
> > rubber parts on them to create the seal to stop the flow of coolant, and
> > was wondering if there is a seat inside the monovalve housing that could be
> > pitted or corroded that could be causing the rubber parts of the valve to
> > not seal properly. I have never taken one of these apart. Any advice is
> > appreciated. I'd like to fix this once and be done with it for a while.
> >
> > Thanks,
> >
> > Jim
> >
>
>
> Pacific Daylight Time,
> > jim@ writes:
> >
> >
> >
> >
> > Howdy, the monovalve on my 84 300D lets coolant through all the time, never
> > completely shuts it off, raises the air temp 10 - 15 degrees at its
> > coldest setting when it should be shut off. The valve was replaced a couple years
> > ago by a Mercedes shop. Seems too soon for it to have gone bad, but who
> > knows.... I see that those valves have rubber washers or o-rings or whatever
> > rubber parts on them to create the seal to stop the flow of coolant, and
> > was wondering if there is a seat inside the monovalve housing that could be
> > pitted or corroded that could be causing the rubber parts of the valve to
> > not seal properly. I have never taken one of these apart. Any advice is
> > appreciated. I'd like to fix this once and be done with it for a while.
> >
> > Thanks,
> >
> > Jim
> >
>
