W126 vacuum dash pod actuators - PeachParts Mercedes-Benz Forum

Johnhef · #1 12-10-2008, 08:20 PM

Awhile back I remember finding a site that sold just the internal rubber diaphragms. Of course now that I need some, I cant find it, anyone know of a source for these?

I finally tested all mine tonight and found I've got 5 of them that are blown. That adds up quickly if I have to buy the whole thing.

Also, Does anyone have the vacuum diagram? specifically color coding of the lines etc, that would be a big help.

Thanks
JH

tinypanzer · #2 12-10-2008, 08:46 PM

Probably doesn't matter, but what year/model?

If you get back to me before midnight (eastern) then I can probably post that tonight.

-tp

Johnhef · #3 12-10-2008, 10:33 PM

1983 500SEC

two duals, and 3 singles iirc.

shadetreemechan · #4 12-11-2008, 08:02 AM

You can get pod rebuild diaphrams from Performance Analysis, 865-482-9175.

tinypanzer · #5 12-11-2008, 02:19 PM

It's gonna be way too big to post here. PM me your email address. I will send as a .pdf file.

-tp

Johnhef · #6 12-11-2008, 09:16 PM

its my username @comcast.net

Johnhef · #7 12-11-2008, 09:19 PM

Quote:

Originally Posted by shadetreemechan

You can get pod rebuild diaphrams from Performance Analysis, 865-482-9175.

Google lookup shows that as George Murphy's phone #. I've emailed him already and am waiting to hear back still.

450slcguy · #8 12-11-2008, 09:33 PM

Some pods are not rebuildable.

tinypanzer · #9 12-12-2008, 05:54 PM

Tried to email them to you - the emails bounced.....

-tp

Johnhef · #10 12-12-2008, 10:42 PM

looks like i'm going to be digging them out of my parts cars hoping to find some good ones to use. I've got a carshow on the 20th and can't take it looking like it is now...

RF_126 · #11 12-13-2008, 07:50 PM

George Murphy can be a little elusive at times, but once you do make contact he'll ship the diaphragms out right away by Priority Mail. I used his product to repair all six vacuum pods in my 500SEC this summer. In my experience they work extremely well, but there is one problem that requires a little more work than his instructions prescribe.

The new diaphragm for the bottom half of the double pod, which George refers to as part #2020, comes with a little internal, plastic retainer cup. In theory, the cup and new diaphragm are simply pressed into the bottom cavity. In practice, that isn't nearly secure enough to work: as soon as you apply meaningful vacuum to the repaired pod, it will come apart. Behr didn't make the original pod that way; clearly, something stronger is needed. I discussed this problem with George, and a couple of solutions were bandied about, including glue. But what I ended up doing, and hopefully the attached photo will help clarify this, was to drill a small hole into the center of the bottom cavity and then screw the new diaphragm and its cup down with the assistance of two carefully chosen panel washers. The largest of these washers fit perfectly around the raised, central section of the diaphragm; the smaller washer applied force to the larger one underneath, pressing the whole assembly very securely together and making leakage impossible despite the creation of a small screw hole in the new diaphragm.

Permissible leakage from these pods is specified by M-B at 30mbars/min at 400mbars. When repaired properly, these pods will lose next to nothing over a period of several hours. In fact, I suspect that what little leakage I do see is caused by an imperfect connection between the vacuum gauge itself and the pod being tested.

Johnhef · #12 12-13-2008, 09:59 PM

I know exactly what you mean. Today I removed the 4 pods I needed from my parts car and 3/4 of them we're good. I took apart my old one, hoping to be able to make one good one since the opposite diaphragms were ripped in each similar pod. I couldnt for the life of me seperate that plastic cup from the other piece to get the old rubber out, without destroying it, and even still, I gave up on it with it all mangled up. I removed the third vertically mounted pod which was still good and am just going to grind off the rivet on the rod and swap over the correct rod from the old housing and make it work that way.