Monovalve movement

[Jack M]

Hello,

I have 3 mono-valves (The Moving plunger) and 2 mono-valve Solenoid Bodies ( the part that mono-valves go into.)

How much movement should there be if you apply 12v dc to the solenoid?

Each combination of valve and solenoid body produce a different amount of movement.

Would some explain to me how the water flows and how the valve actually functions.

Thanks, Jack

[ericdee]

They govern the temperature by pulsing. What exactly is the problem? Year and Model would be good to know as well?

[Jack M]

I have a 1869 560sl 147K.

I have replaced the valve twice.

The heat and AC always worked well for 7 years of ownership. New valve does not move as much as old one did .
It's really annoying to pay $40. for a 50c rubber diaphragm.
OK I understand the pulsing and the grounding operation.
What I want to know is: Does the plunger on the valve seat fully?
( I would certainly think it should, as not seating allows hot water to flow.)
So If it does not seat, then hot water is flowing when you don't want it to, right?

Please explain the operation of the valve and how it corresponds to the setting of the temperature wheel on the side of the PPU. and the cabin air sensor on the dash.

Or direct me to a tech report to read. Thanks all.

[RadioTek]

Just FYI: there is supposed to be a monovalve rebuild kit available from the online parts houses. Last I heard was around $27.00.

Hope this helps someone

[Jack M]

Hi It's not the mono-valve itself that I want to learn about. It is why the action of the solenoid is different between the different mono-valves and the solenoids when it comes to moving the plunger.

Each of the 3 mono-valves move a different distance when voltage is applied to the solenoid. Six possible distances moved. Which one would be the best?

Is the rubber plug at the bottom of the mono-valve supposed to mate with the seat at the bottom? Thus stopping water flow?

When I order my next one which Manufacturer?
Or be sure that it is Bosch.

TG this is little stuff. Jack