Dave, thanks for the information. I'll give Pelican Parts a try.

Hi All - I went to order the rebuild kit for the center pod from Performance Analysis | Climate Control | Diaphragms | Blower Motors | Pushbutton Panels | Vacuum Door Locks | Autotemp | Cruise Control | Engine Oil Analysis | Mercedes-Benz Parts | Mercedes-Benz Club of America | Oak Ridge | Car Care[/url]) and they said I should order rebuild kits for all the pods, except for the oval/rectangular ones. Before sending the paypal I came accross this post so I emailed the the above text to them to get their input. Below is their response:

"That description at Peachparts.com is not accurate – my diaphragms fit and operate properly all three double diaphragm units and the single diaphragm diverter and center nozzle flap actuators. The stroke with new diaphragms from us appears shorter at first, but when they diaphragms are operated a few times the rubber stretches to provide full stroke.

Also, some customers have not re-assembled the actuator properly after re-assembly, which cause short stroke."

The response seems pretty legit to me so I think I'm going to buy as many of the rebuild kits as possibly for my 1992 300D. Has anybody ever tested the pods for an extended period of time to verify that they loosen up a bit - therefore providing the necessary amount of stroke?

Having disassembled & reassembled these pods, examined the design of the rebuild kits, and bench tested them next to new pods... I stand by my original statements. I also do not believe the rubber stretches over time to significantly change the stroke on the dual-chamber pods. Note that he doesn't specifically answer the exact question, btw.

However, I would love to get a second or third opinion. I wish I had videoed or photographed the difference ten years ago when I did this. I'm not interested in buying another rebuild kit, but if someone sent a kit to me, I'd be willing to document / photograph / video the "reduced travel" phenomenon.

UPDATE: Turns out I still have two unused repair kits for the dual-chamber large lift portion. I also had a disassembled pod to inspect. From a quick test, I still believe my original claim of reduced stroke is correct. However, I will work on better documentation this time, including exact measurements of the difference in stroke. Stay tuned.

Sorry this took so long, but I finally rebuilt a pod using the Performance Analysis Company ACD-2020 dual-diaphragm repair kit, and photographed it next to an OE, unmodified pod. The travel is almost exactly half as much as the original.

Full photos are at this link. The two main photos are below.

Again, the ACD-2010 repair diaphragm works perfectly, it's only the ACD-2020 kit which restricts travel. Out of the dozen or so dual-diaphragm pods that I've replaced, almost all of them still have a good "large lift" diaphragm, so you probably don't need the ACD-2020 kit in the first place. It's the "small lift" diaphragm that usually fails, and the ACD-2010 kit is an economical way to repair the pod.

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Dave
Boise, ID
Check out my website photos, documents, and movies!

Resurrecting an old but very useful thread. With the help of this thread I have jury rigged my vent system to start working again. Have had an issue where I only have flow from the side vents, and some through the defroster. I presumed my center valve pod was probably shot. Key bit of info in the thread was that this is the default if no vacuum is coming to the vacuum valve manifold behind the airbag/glovebox.

So I pulled the airbag and dug out the trusty Mitey-Vac. Pulled off the top feed to the valve manifold and sure enough, no vacuum when the engine was running. Pulled a vacuum on the manifold with the Mitey-Vac and voila, suddenly I had full air out the center vents - Yes!! And the line to the center vent held a vacuum nicely when pulled down directly with the M-V.

The main vac line to the valve manifold was green. Fed from a Y located above-behind the master cylinder. Checked for vacuum there, no joy. Tested vacuum from the pump, beaucoup vacuum there. So it seems that there is some break in that line, which I could not trace. (did not try from underneath because lazy...) So I elected to put a spare Y fitting in the line just after the T tap line above the pump, and ran a new vacuum line to the Y behind the master cylinder, and voila, vents working normally. Next oil change when I'm underneath, I'll try to trace that non working vac line.

Rgds,
Chris W.
'95 E3000D, 447K

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Objects in closer are mirror than they appear.

It's been a while but after reading this thread, I swapped in used MBZ diaphragms for the dual piston pods. I couldn't help it. I'm cheap, new pods were ~$70 each, the pods can be accessed without much trouble and I have bigger climate issues than a semi working vac pod. Thus, a half fast attempt at a cheap repair was better than an expensive(er) repair. The pods hold vac and seem to be redirecting the air flow.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

I know this is an old thread but I'm currently up to my neck in this project and this thread has been my Bible. Anyway, it seems the center vent pod, 124-800-02-75 is NLA from Mercedes. I found one supplier online who claimed to have it, and at a really cheap price. I thought it seemed to good to be true and it probably was because they took my money a month ago but haven't sent the part.

Anyway, the advice I got from someone is that this part is the same pod as 124-800-03-75 and you just need to switch the arm over from the original part. 124-800-03-75 seems to be readily available at a number of places so maybe this will help someone.

Nooooo! This is not correct. The -03-75 pod is round but otherwise has nothing in common with the -02-75 pod. The -03-75 is physically smaller, uses a different diaphragm, and has different mounting. You can't swap the internal parts either.

The only current solution for repairing/rebuilding the -02-75 center vent flap actuator, which is indeed NLA, is buying a replacement diaphragm from Performance Analysis. Their part number is ACD-2010, last I checked these were still $6 each (plus S&H):

http://www.perfanalysis.com/climate-control/acc-version-ii/

Interesting. The "someone" I got my advice from was Performance Analysis (I didn't want to appear to be giving a free plug). They told me their replacement diaphragm kits are only for the other pods and will not fit the 02-75. That's when they mentioned using an 03-75 by switching the arm over from the original 02-75.

I think they must have gotten their part numbers mixed up. Their diaphragm kit works great on the pod for the center vent flap, buried inside the heater box, in front of the heater core.

Their diaphragm kit will not fir the smaller pod for the diverter flap, located on top of the heater box assembly. This pod is still available new so at the moment it's not an issue.

For reference:
124-800-02-75 - Center vent air flap control - Larger diameter round pod, rebuildable, NLA (No Longer Available) new
124-800-03-75 - Cold air flap control (diverter) - Smaller diameter round pod, not rebuildable, still available new

Ok, thanks for the clarification. I guess I'll call them again Monday to order the kit. I knew this couldn't be that simple but I'm glad this thread is here at least. Thanks!

OK, just spoke to George Murphy and he says he no longer makes that kit. Now what? I've got a car torn apart, all the other pods replaced (which were all still working, go figure) and the one pod I really need I can't find or fix.

The normal size 2010 diaphragm he does not sell anymore?

Well, I guess you could just buy a face vent assembly for the W126 and steal the guts. PN should be - 0008006775... reason I suggest that one is I have used the Performance Analysis diaphragm to rebuild this one more than a few times on my W126s.

Curious to the outcome here.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

What I'm wondering now is if a pod from a 190E would have the correct size diaphragm that I could swap over. Assuming it's also not NLA.



Are you saying a W126 face vent assembly would furnish the parts to rebuild my pod, or that I could swap the guts directly over?

Wha...??!! That's not good. Well, I think the 2020 kit includes both diaphragms... if he still sells that kit, you could buy that and get the diaphragm you need (and toss the other one). If he doesn't sell any diaphragm kits, shoot, that is depressing news.

Otherwise yes, if someone could find a pod from a different chassis that uses the same diaphragm, you could buy one of those pods and swipe the diaphragm from it.

I believe another option is to buy one of the dual-diaphragm pods for the 124 (defrost or main air flap) and take the front diaphragm out to fix the center vent pod, but those are pretty spendy to part out ($40-$50 each).