hvac vacuum actuator replacement diaphragms
 

Has anyone tried these?

http://www.autoluxmbz.com/

Made for Mercedes but I'll bet it's all the same. I have three dead vacuum actuators - defrost, heater, center comb flap - and I do not want to pay the high price for replacements.

I'll also bet this is better rubber.

John Pirtle
87 a/t 196k
http://members.rennlist.com/pirtle

John,
Great find and I hope they work.
Just spoke with the owner - Jack Eldridge - and he is real keen to look at our different vacuum pots and respective diaphragms.
I will send him two actuators tomorrow and he will let us know if his current units fit or if he can mold new ones.
I am so fed up of throwing away complete plastic pods after using the diaphragm.
Roger

ROG,

Thats awesome... fingers crossed. I sent him an email ealier...

$5.30 per kit is very cheap....some Porsche actuators are $75!!

John:

Did you determine the dead actuators by Mityvacing the colored lines in the driver's footwell? I did the same tonight and all hold vacuum. However, I cannot get my air flow to go to the footwell. It only goes to the center comb and defrost.

Best of luck with your parts!

Peace,
Tim

JOhn,

Didn't you already replace those on your S4? I used your info to replace 3 of the 5 (including heater actuator) on my 79. Ditto to what Rog said, if these work, what a friggin find!!!!

Tim, I once had a problem with no air flow to the footwell. It turned out that I had pushed the yellow line (footwell) too far into the rubber elbow - so it couldn't get any vacuum. :)

Also make sure you have the right lines connected to the correct solenoids.

Yes, I had replaced the center comb flap, footwell, and recirculation actuators. It's been about 4 years and 60,000 miles.

http://members.rennlist.com/worf928/lurk.gif

Volume order potential here...

GREAT NEW!!!!!
 

GREAT NEWS!!!!!!
I sent Jack a couple of the diaphragms - one small and one large - and the large is identical to what he has already. He is sending me some to play with.
He now wants the pots themselves which I will take care of.
He is interested in making the small diaphragm as well.
Question - how many different diaphragms are there on our cars??
How many are the same as 911, 968 or 944 ????
Jack is motivated to resolve this problem and we get cheap diaphragms instead of buying complete pots.
Any input welcome.
:jumper: :jumper:

That’s great, I have his diaphragms in my 500 SEC and 300 SDL Mercedes and they have been working great!

Although you don't really need the "POD POPPER" I have that as well :)

FWIW, Jack Eldridge is well known in the MB DIYS community.

Hey Roger,

timing is excellent, the vacuum actuator in my recirculation flap just crapped out. I'm in on this for sure.

Great find.

Paul

Awesome! I need three cars worth of 'em probably! :jumper:

Roger Doger,

I've been through (almost) all the actuators on mine. I'm going to replace the footwell on the 79 (last one to replace) The OBs, and I'm talking OB OB (77-79) have one more than you do on the later cars. 5 on OB OB vs 4 on later model with auto HVAC (including the heater valve) There are only 2 different sizes. (A large and a small) So if this guy can do it, let's go BAby!!! :jumper: Order as many as you can, I'm sick of paying out the frickin wazoo for these be-hoches!!! :rtfm: BTW, what is the pod popper?? I've just been jacking with these until they come apart. like a friggin fortune cookie!!!:eek:
I have several good pots if you need them for a core. :thumbsup:

Dude, this could be the next best thing to Ford motor mounts!!!! :cheers:

What size diaphram is on the comb flap actuator? If it is the large I'll order one from this guy today. What is the part # for it?

Flormat,
That one is small I belive.
Roger

Chuck,
Been counting and I think there are 5 on all my cars.
Two in the console, one above your left knee when driving and one for the recirc flap. Plus the heater that makes 5.
Wally P lists them all in his HVAC writeup - I will check it.
I have some samples of the larger diaphragm - I need a couple of volunteers to try them out in anger and report back.
Any one need to change a large vac pot?
Roger

Hey Roger,

my recirculation flap is in need of a new diaphragm.
I'm ready to do it as soon as my car comes back with the new compressor.

Paul

I'll take a truck load, do them all while I'm at it and be done with it for another 19 years

I only have two spares - one for Champagne and one for NickT.
Nick PM me your address please.

PM sent.. It will be wonderful if these things work... Fingers crossed.

Thank you Sir ;)

This couldn't be better timing. I just pulled my console and 4 outa 5 vacuum lines failed so I'm about the start the repair process. Please keep me/us informed. I can take what ever sizes are necessary and do a test tomorrow.

Thanks

Gordon

Any update on whether these work or not?

Thanks

Gordon

Oh Man! I just replaced all of mine, and it wasn't cheap. :banghead: Hope they're still around in 18 years.

They are in the mail en-route to Nick and Paul.
We will have to wait and see.
I am trying one on one of my cars - should know something tomorrow.

Part ACD#2010 on the Autolux site fits the Recirculation Flap Pt No 928 573 077 04.
The complete assembly is currently $20 and the diaphragm from Autolux is $5.30.

The Defrost Flap diaphragm is slightly longer than the above part, however I will see if it fits and works.

The Center Vent and Defroster flap diaphragms are smaller and Jack is possibly going to make them. I will be sending him some old complete actuators for him to work on.

The Autolux part in the last post does not fit the Defroster Flap.

The "heavy hitters" price wise are the two small actuators (Center & Footwell) at $80 and $64 each respectivly. However as you only need the diaphragm purchase the cheaper unit for this as they are both the same.

I think you can pretty safely assure him that there will be a market for them if he does. I know I'd be buying.

Roger, many thanks. I will begin the process and place orders where I can. There might also be a market for rebuilt using the core in exchange, saving some the hassle of ear down.

Gordon

some of them are riveted in.

btw I would greatly prefer electric servos :)

Gordon,
I agree with H - it is far easier to change out the diaphrgm than the complete unit as they are rivited in place.
Roger

We still on for this weekend?

Thanks John for the HVAC Actuator replacement write up on your site, it has been invaluable.

Thanks to Roger for supplying the large diaphragms.

Did the guy ever make the smaller ones?

Did the guy ever make the smaller ones?

The "guy" was me - Roger@928sRus.com - and no I did not due to the high tooling cost.
I have the rights to the sale of Porsche Recirc. diaphragm - for what that is worth.
They are $10 each including shipping in the USA in most cases.

Still working on the smaller diaphragms and I WILL get them made somehow!!

Impressive Rog :) Yes, it is amazing to have an inexpensive source here locally for those silly diaphragms!! :thumbup:

They are not interchangeable, your choices are to take your chances with a correct used vacuum pod, replace the entire recirc box for a 84' and up, or retrofit the new style vacuum pod into your recirc box. I chose the latter.

New style diaphragm on left.
https://cimg7.ibsrv.net/gimg/rennlis...07bf8cf3aa.jpg

Old style vacuum pod attachment method. Pry off the metal retainers with a screwdriver.
https://cimg3.ibsrv.net/gimg/rennlis...38e5327e39.jpg

New vacuum pod clips onto the recirc box with four plastic protrusions
https://cimg3.ibsrv.net/gimg/rennlis...3c7c0da855.jpg

I applied a pattern to enlarge the center hole and for the mounting points
https://cimg4.ibsrv.net/gimg/rennlis...ce19d3e418.jpg

I did my best but it is awkward to get at with the ledge above.
https://cimg8.ibsrv.net/gimg/rennlis...7abb961317.jpg

https://cimg5.ibsrv.net/gimg/rennlis...07ba86d955.jpg

It was a pretty secure fit but for piece of mind I JB welded the base of the vacuum pod to the recirc box. If the diaphragm ever goes bad again you just replace the innards anyway.
https://cimg7.ibsrv.net/gimg/rennlis...5ae5df9128.jpg

Retrofit complete.
https://cimg6.ibsrv.net/gimg/rennlis...3b7ed0ea2f.jpg
It works perfectly.
After I wrote this out I found the discussion thread https://rennlist.com/forums/928-foru...acuum-pod.html

Nice work Mr. Moose. I say never be too proud to use JB Weld in the right circumstances.

I hope Roger will chime in here and correct me if I am wrong, but I believe he has the "smaller" diaphragms for the comb and footwell actuators made out of a superior silicone rubber but only has the entire actuator for the "larger" defrost and recirc flaps. For cars with the "snap in" recirc actuator old threads indicate that a Mercedes "single" diaphragm available here - http://www.perfanalysis.com/climate-...acc-version-i/ - will fit the recirc actuator. I have not verified this but have an example being shipped to my hacienda.

Are the diaphragms for the recirc and defrost interchangeable?

Alex & the Group --

From your pictures it looks like the diaphragm for the replacement actuator is a tad shorter in the cup than the original, has same length rod/link attached, and same diameter as the original. If this is correct, does the new part have the same available stroke as the original? I'm trying to remember if/how this might be important for the recirc flap especially. I think that's the only one I haven't replaced.

I cannot say for sure, I replaced the whole unit. I could take apart the old defrost vacuum pod and measure the diaphragm if that helps.

The new part has the exact same stroke and fully opens and closes the recirc flap.
If this is for your '89 then it should be a direct swap, no retrofit needed.

I used to sell the diaphragm for the recirculation actuator - Mercedes part and it was similar but not exact dimensionally to the defrost diaphragm.
Some were able to fit it and get it to seal in the defrost position but many others could not.
As the recirc. and defrost are relatively inexpensive as complete actuators I have not really looked for a replacement diaphragm.
I do have the diaphragms for the footwell and center actuator (in the center console) for $56 each.