Heater Core Valve Control Arm

[DavidAPease]

In my never-ending preparations for my cross-country trip, yesterday I decided to go through the heating system.  As have many others, I found my heater core valve frozen.  While I was able to use the excellent descriptions found on this site for how to build a tool and remove the valve, I have (of course) another problem.  In my car, when the valve froze (who knows when - I don't think the heater has worked properly since I've owned the car), the arm that turns the valve gave way.  This is the arm with the ball connector at one end and the square hole that fits over the valve on the other.  The metal around the square hole simply split, and appears unrepairable.  I have looked at both the Mercedes and Niemoller parts catalogs, as well as several online sources, and have not been able to find this part.  Does anyone have a part number for this arm, or know if it's still available (or have a spare one lying around)?  Thanks for any help,

-David Pease
'66 French 230SL

[A Dalton]

Hard to find part and unfortunately a sedan one will not fit ..
 I had the same problem on one and wound up brazing the old and cutting the hole square again with a fine file.  Not as hard as it sounds, so if no one has a used one, it is do-able..

[Cees Klumper]

A previous owner of my 280 SL did the following to remedy the frozen heater core valve. He placed a manual shut-off valve in the hose going to the heater. In the summer, I close it, and in the winter it's open. I get good heat in the winter, and no unwanted warm air in the summer.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[A Dalton]

quote:Originally posted by cees klumper

A previous owner of my 280 SL did the following to remedy the frozen heater core valve. He placed a manual shut-off valve in the hose going to the heater. In the summer, I close it, and in the winter it's open. I get good heat in the winter, and no unwanted warm air in the summer.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

 That works .. they have generic ones now that do the same ,but they  have a cable to allow  for operator  cabin variable flow.

 On the original, the link arm for the valve control  comes off an air flap , so that has to be considered .  I imagine it just gets disconnected at that point?

[Naj ✝︎]

quote:I imagine it just gets disconnected at that point?

There is a ball stud on the left air flap which breaks off when the heater lever is forced to try and open a stuck heater valve.

naj

65 230SL
68 280SL

[A Dalton]

quote:Originally posted by naj

I imagine it just gets disconnected at that point?

There is a ball stud on the left air flap which breaks off when the heater lever is forced to try and open a stuck heater valve.

naj

 Yes , That is my point .  If one uses an inline hose valve in place of a stuck/broken valve , they would want to disconnect the ball from the flap or valve pivot so one still has  flap operation without causing damage to either the ball/rod or , more importantly, breaking the lever ..

[ted280sl]

David,
  I believe I had the same problem. I purchased a new flap with the ball attached to repair the damage to the linkage. That is a relatively easy job although the cost of the replacement flap was expensive. Before you replace the flap you will need to unfreeze the valve. This will require a replacement "O" ring which is very inexpensive. The real problem is unfreezing the valve. In my case I had to remove the heater core and take it to a radiator repair shop for them to heat it up and eventually hammer the valve out. I believe that removing the heater core has been detailed previously on this website. If you elect to follow the procedures not only will you have the satisfaction of having a properly working heater valve but, you would be joining a selct club of pagoda classic car fanatics who have gone where most rational people would never dare. I would estimate the time needed to remove and install the heater core at 10 hours once you know what you are doing.
Best of luck,
Ted
1969 280SL w/ a properly functioning heater core valve
Member of Pagoda owners who have removed the heater core club