Vacuum element for fresh/recirculating air flap - 1983 300CD-T
 

The vacuum element for controlling the fresh/recirculating air flap has (finally!) failed on my 1983 300 CD-T.

Despite removing the glove box and panel that fits above the passenger footwell,I am unable to determine precisely how the vacuum element's actuating arm actually attaches to the flap.

Question: Does the actuating arm perhaps hook onto the flap? Is there a clip or pin to remove?

The FSM says, "Unclip actuating linkage on recirculating air flap." Hmmm. Can anyone shed a little more light on just how I will be disconnecting/re-connecting the actuating arm?

Thank you-

If it is similar to my 1987 300D Turbo (W124, OM603) -- and I don't know that it is -- the pod's arm is attached to the flap by an expanding plastic pivot point. There is no pin, clip, or fastener to remove, you just (carefully) lever the two parts apart using a thin-blade screwdriver.

For a picture, search for Sixto's thread "87 300D recirc and defrost pod replacement" and scroll down to picture #13.

Jeremy

I understand there is an arm with a wrist pin type affair.

Thanks for the information.
I’m looking forward to shoving a small mirror in there as soon as I have enough access so that I can see exactly how those engineers configured the point of attachment. Most likely, after seeing how it is set-up, I’ll think, “Well of course! How could it have been any other way?”:)

Apparently the climate control system was assembled separately (probably by a subcontractor) and then put into the car as a unit. Service, therefore, is supposed to be just the opposite--take the sucker out and operate on the workbench. No way are we gonna do that, of course, hence the "smoke and mirrors" needed.

Digital Camera
 

I used the mirror method for almost 50 years. I now find a digital camera works much better.

I went through this a few months ago. One of my major leaks was that particular element. Just getting the element loose was a major PITA. After almost giving up I found that the "arm" is hooked to the "flap" by a "hookey, elbow thingy" (in Sarah Palin terminology). I cannot remember exactly which way it goes. But, once you have that actuator loose you can work it around and just push the arm out of the small hole in the flap. I want to say that I pushed towards the firewall to get it out.

I actually have mine safety wired open and the hose plugged until I take the time to buy new diaphragms.

Edit: Oops.... Almost forgot. There is a bunch of foam crap on that flap. You will knock most of it off trying to get the arm off. It will fall into the abyss. If you remove the blower motor first, it will just fall out and you can wipe the rest out with a rag.

Back to the tour....

I have already undertaken inspection under the dashboard with glove box and panel removed and if you could see what I and the wife (she's rebuilt the brakes and done other work on the car - she bought it in 1985 and is no wuss about working on the car:P) could see, you would likely discover that a digital camera is of little help in the existing circumstance. I already tried it. You may have a copy of the picture if you would like to ask me for it. Due to various angles and matters of negligible clearance, there is no way to see the point of attachment of the vacuum element's actuating arm to the flap until the element's rotational disengagement from its bracket is completed. I surmise that this step completed, a small mirror could be positioned in order to peer around the corner of the climate control housing which contains the flap and the point of attachment could then be spied.

You don't need a camera or a mirror. Break the element loose, and maneuver the arm around so you can get the "hook" out of the flap.

If you can break the element in half (so you can move the arm around more) it makes a big difference.

Once you do it... It will be one of those DUH moments...:D

My notes on replacing the elements.

http://www.peachparts.com/Wikka/W123HVACVacuumActuators

Dave

Any more advice on how to wire it open? Mine is now stuck closed for some reason.

The part number in Fastlane is W0133-1614393.

Note the 90 degree bend on the end of the actuating arm revealing something about how it attaches to the flap.

Thanks for all of the help.

Actually I guess the proper term would be safety wired shut. I simply removed the element from the car, broke the element in half, re-installed the arm back into the flap and safety wired the arm to the "element bracket". This holds the flap shut so you cannot put your hand into that opening. In this position Only fresh air is allowed into the car.

I actually have found where to get the new diaphragm's to fix it. I have just been driving the car too much to mess with it right now. You can re-use the old elements and just replace the diaphragm's.

I'm considering the opposite: wiring mine to allow only recirculated air. Down here, AC is the biggest need. Any reasons not to?

I have found that the car de-fogs better with it wired for fresh air. Especially with all the rain we have been getting. Super humid. With it stuck in the recirculate position it would take a long time to de-fog. Living on the water makes it worse. Not to mention it stinks in there. I still need to clean the evap. coil and wash it out. 24 years of crud on it.

I'm not too worried about the cooling. With the thing wired for fresh air I am getting 35 to 37 degrees at the vents. I doubt that it could get much better than that.