[W126 Coupe] regarding front windshield discussion

[Gerry Van Zandt]

Dick,

Thanks for a very comprehensive overview on the vacuum pods, their  
location and function. I was preparing a similar (though less  
extensive) note regarding the pods until I came across your note, so  
you saved me the time and effort. Thank you very much for doing this.

I always recommend to people just to buy all new pods rather than  
rebuild them because of the fact that they are fairly inexpensive to  
buy new, readily available, and you don't have the additional hassle  
and time of rebuilding them with the Murphy kits (which as you say,  
do work well). I also advise replacing *ALL* pods at the same time,  
so that everything is known-good (eliminating any pod-related issues  
for at least the next 10 years) and thus if any further CC issues pop  
up, the new pods can generally be eliminated as a cause.

Typically and generally speaking, I see monovalves being an issue  
with heat/cold problems, and the vacuum pods generally being the  
issue with flap/air location control issues. The pushbutton units do  
go out but I would say less frequently than the monovalves and pods -  
simply because of the degradation of the rubber seals in those parts.

The vacuum pod issues also extend to the 124 (1986-1995) E-class cars  
as well as the US-spec R107 560SLs (which I believe were only sold in  
the USA, Canada? and perhaps Australia) all of which had the very  
similar ACC system to the 126 coupes and sedans.

126 Coupe owners should also be *VERY VERY* thankful that they do not  
have the major CC issues that R107 SL owners with ACC do. Namely, not  
merely the existence of the vacuum pods in the dash, but the  
existence of one of the pods INSIDE of the airbox in the dash behind  
the center console. This is doubly or triply compounded by the fact  
that this airbox cracks and leaks, and is extraordinarily difficult  
and expensive to replace. The entire dashboard and front-interior of  
the car must be removed to perform this job, and repair can take an  
experienced tech several full days of labour, not including the time  
required to either patch the airbox or procure it from MB. There is a  
semi-easy fix that many mechanics do that allows the system to  
function at 90% of original capability, which is very inexpensive to  
do and that most owners end up going with.  But if you've ever been  
in an MB shop and seen a 107 SL with its entire dashboard and front  
interior removed/disassembed, you will know what is happening. Major  
CC surgery....

Cheers,
Gerry

1994 E500
1989 560SEC
1987 560SL



On Nov 28, 2007, at 9:15 AM, mbcoupes-request at mbcoupes.com wrote:


> Gary:

>

> I should also mention that if you live in an extremely humid climate

> with AC running, some small contained area of condensation on the  

> lower

> center of the windscreen is normal.  Your defrost air flow should be

> relatively light in all modes except where defrost is selected on the

> pushbutton control where air flow will blast the windscreen from the

> defrost vents.

>

> Dick