In my never ending quest to repair my Euro (non ACC) climate control I again purchased Mono-valve Inserts online. I had replaced these Bosch inserts three years ago, but to my surprise the rubber diaphragms recently died. Unlike the last ones that were Bosch, the brand I received in the mail unknowingly was Ronak. I installed them only to find out that the heating problem did not really go away - Not thinking there would be any fault with new inserts I started some major and sometimes painful investigating elsewhere. In the process I first cleaned and then replaced the Valve itself with a salvaged unit, took out and repaired the Aux. Water Pump and learned about Electrical Pulses and temperature selector wheels more than I ever intended too. With help from many members here.
I have now come full circle to believe that perhaps I got what I paid for - A less expensive but no good insert. The Ronak insert is definitely ever so slightly shorter than than the Bosch, though perhaps that has no meaning. Before I go buying more inserts and making these assumptions and accusations I was wondering if people here have good experience with after market brands, or does every one stick with Bosch which is much more expensive.
Still hoping to find a cure...

1987 300SE Euro
These are two earlier threads where I tried to figure things out -

126 Mono/Duovalve again...
Can the 126 Monovalve Leak ? (Not the Insert).

Gidpor:

I was curious about this myself, that is curious about "Ronak".

The following URL is a pointer to all threads here with the word "Ronak" in them. I saw mixed reviews regarding Ronak. After reading these threads I decided Ronak would not be my first choice.

Just my 2 cents.

http://www.peachparts.com/shopforum/search.php?searchid=322682

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Bosch! Bosch! Bosch!

There are MANY brands of counterfeit aftermarket parts available for any car! Most are less than a quality part that should be installed on a BENZ!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

OK, I will order new Inserts yet again - specifying Bosch and hope that will do it. I am still curious though about the mono or duo valve and some of it's functions. Can anyone explain where does the small hose lead too that is connected to the red circle in the photo. This seems to always carry hot water and essentially bypasses the valve itself. Is it for the windshield heater ? What would govern the heat generated by the water from that hose? thanks for any insight.

I forgot to mention - The blue box that contained the Ronak inserts, also has written on it M.T.C#3065, so it stands to reason that ronak=Mission Trading Co.

Attached Thumbnails