Haven't been here in a while, but it's time now to replace all the vacuum pods in the dash. Suffered through the summer here in Phoenix with the A/C blowing through the defrost vents. Not gonna go through another summer without center vents.

Mine is a 1992 W124 - 300CE, and I don't know whether it has a cabin filter or not. Here's what I found on "auto-haus-az-dot-com" for my model/year.

124-800-03-75 Vacuum Element; For Climate Control Cold Air Flap
124-800-02-75 Vacuum Element; For Control of AC Shut Off Flaps
124-800-09-75 Vacuum Element; For Control of Left Legroom Air Flap
124-800-26-75 Vacuum Element; For Defroster Flap

Apparently, they don't have the recirc/fresh air pods. You may have answered my question many times, but wasn't able to find it quickly. So, here goes... Are the recirc/fresh air pods accessible with the dash in place and if so, or not, are they typically bad when being replaced?

Thanks!

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1986 300E - 230kMi (salvaged parts available)

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It does not have a cabin filter. Only 1994-95 model years have the filters. These models also use different main/fresh air (recirc) pods (the shafts are different, I believe, the pods should be the same).


Yup, theY do have them, but you will need to search by part number, not via their model/year catalog. They are the #04 and #11 mentioned in my list above.


The only pods which can be replaced with the dash in place are the footwell and defrost. Since you want to fix the center vents, you will have to pull the dash. And if you do that, you should replace ALL the pods, even if they have not yet failed; as you will not want to pull the dash again in a couple years to replace the next old/dead pod.


On a side note, it appears that a couple of the pod numbers are different based on model year and/or VIN. My original list in the first post applies to 86-89 and early 90. The defrost pod changed part numbers (from #00 to #26) in late '90, I believe. As noted in the original post, the models with dust filter (94-95) have different part numbers; although I strongly suspect it's just due to the flat metal shaft, which I don't replace on the main air pods anyway - it's easier to leave the old ones in place and just replace the pod itself. You'll see what I mean when you get in there.

As a side note and possible mentioned earlier in this thread, Jeremy and the FSM indicate a diffierent footwell pod setup for early 87 300Ds, Jeremy's being such a car. The old style has two pods actuating the footwell flap.

Sixto
87 300D

Correct. This applies to all 1986 and early 87 chassis:

124-800-01-75 - Footwell flap control (Round, 2 required) - Up to VIN 289309
OR
124-800-09-75 - Footwell flap control (Rectangle, 1 required) - From VIN 289310

Can the pod be bypassed? Opened all the way, 100% of the time and then the vent operated manually with the dial on the dash?

I am sorry to open this issue again. I believe there were directions on the boards here to bypass the vacuum pods and simply manually operate the center vents with the dial on the dash. I cannot find them. This would also allow heat to blow on my right hand in the winter which might be nice. Thanks for any advice to help me find these directions.

__________________
David
1986 300E Anthracite + ECodes + MB Mileage Award

http://www.peachparts.com/Wikka/W124HVACVentMod

And you should be sorry to open this issue again!

Sixto
87 300D

With all due respect and great humility that write up is amazing. Awesome. Tawdry.

I am actually thinking of another post. Something along the lines of:
1) Disconnect the vacuum line to the center pod
2) Block that line closed with a chopstick or something
3) Remove center louvers
3) Reach in through the center hole, find the 'pod' flap
4) Jam that flap that was operated by the pod open, which a chopstick or something
5) Put louvers back and use the flap on the louvers from now on.

__________________
David
1986 300E Anthracite + ECodes + MB Mileage Award

Easier still than that method is to route source vacuum to the center vent pod. Tap off the ACC vacuum source and route it directly to the center vent line just behind the ACC controls. This only works if the center vent pod holds vacuum. If it doesn't, you'll have to physically jam the flap like you said.

Removing the center vent blinds isn't fun. There's a risk of breaking the spring clips and it's tedious working with the screw that holds the manual flap to the thumbwheel.

Sixto
87 300D

Just read through the thread to help in diagnose my lack of center vent issue and I tested 1-4 on the vacuum block and 1 and 2 do not hold, 3 holds and surprisingly 4, center vents, hold.

I didn't do the rest of the ports because I was stumped why my center vent would hold vacuum. I pumped it to 5" and visually inspected that it was open and holding.

So I put the line back and started the car and put it on EC, temp wheel to min, and fan to high. No center vents.

Puzzled I tested how much vacuum was coming into the 7 port block. At idle its 9" of vacuum and then I decided to test it in the engine compartment, 9-10" vacuum there.

How much vacuum should I be getting at the supply for that vacuum block? I do not think I saw the value anywhere in the 13 pages.

thanks

Vacuum value will change depending upon engine load.

When testing pods at the switchover valve it's simpler than that. Basically if when connecting the aux vac source to the removed hose, if it holds a vacuum it's good, if not it's bad.

With the exception of the defrost vent, which is POSSIBLE with lots of new swear words to replace without remving the dash, replace ALL pods if even one of them is bad. After you finish with this 15 hour job, it will be clear why you replaced them all.

Best of luck with it.

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I know this, I am mainly asking what should the value be for the vacuum supply to the 7 port switch. I do not care that my #1 and 2 lines do not hold vacuum. I just want my center vents to work for the time being.

Trying to figure out if the vacuum supply is weak at the 7 port block or if it is ok. Then I will go from there.

I had center vents a few months ago and now I do not. Plus my transmission shifts like crap at low speeds which also could be a low vacuum issue.

Ideally the car blows up and it rains money in my house so I can get a different car. But until then I just need to know the amount of vacuum I should be seeing supplied to that 7 port block.

On a diesel it should be 20-25" Hg, on a gasser, I'd still expect 15"+ however I've never actually measured it. When I test the pods, I pump the MityVac to 25", not 5". I'm not even sure the pod will fully actuate with only 5". But anyway - you could also check if there is vac output at port #4 with the engine running, temp on max cool. Might be an electrical issue, although it's not common...

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Dave
Boise, ID
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I only pumped it until I saw it open, I guess Its safe to pump them up higher, didn't know.

I may be having a vacuum supply issue then since the green supply line only shows 9-10" Hg.

Again, I'll go back into the dash and check the output with the settings on for port 4.

Dave, this is a great post--tons of good information.

I know this is an old post, but where did you guys buy your parts? I've having trouble finding them for the prices that Dave mentioned ($15-20 for the single chamber and $25-30 for the dual chamber ones)

124-800-00-75 - Defroster flap control
124-800-02-75 - Center vent air flap control
124-800-03-75 - Cold air flap control (diverter)
124-800-04-75 - Main air flap control (Left)
124-800-11-75 - Main air flap control (Right)
124-800-01-75 - Footwell flap control (Round, 2 required) - Up to VIN 289309 (My 124 is Pre 289509)


Dave mentioned Rusty's or Fastlane but I tried to google these with no success. Can anyone provide a link to their webpage? The only place that I've seen them online is: http:/XXXX/searchitem.epc and they seem to be pretty expensive there ($80+ per part). Any information would be greatly appreciated. I'd like to get this project going before summertime rolls around here in Southern California

Thanks,

Shawn

Shawn, the original post was from 2002. Prices have increased dramatically since then. As of March 2013, those pods are approximately $30-$70 each (!!) at most aftermarket vendors; or basically double what they were 10 years ago. The forum owners removed edit capability years ago so I am not able to update my original post.



Fastlane was the old sponsor of this forum, I'm not sure if they are still in business. Rusty was the owner/operator of Buy MB Parts dot biz but he just last month sold his business and went to work for WorldPac (the distributor that many vendors source their aftermarket MB parts from). It's verboten to discuss other vendors on this forum, you'll find their names are replaced by "XXXX" if you try to post or PM about them. Only the current sponsor is allowed to be discussed (at the moment, this is PelicanParts). Pelican does have pretty competitive pricing on aftermarket parts though.

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