Dash Removal Guide, Center Air Vent Solution, How to find Vacuum Leak, 148 pics

[htfan1]

Originally posted by zadefaraj
Once you have them out like in this last pic, you can simply push them upwards and pop them out to test each line individually if you'd like. Keep in mind: the far right one should be the one that supplies the vaccum. Test them all and let me know what happens.

http://www.corpfr.com/c280/P1010193.jpg

zade

The verdict is in:

Three different leaks! Yes, not 1 or 2, but 3. Line #8, #4 & #2 are all bad. #2 & #4 are very bad! BTW, The center vents seem to be controlled by #4.

How difficult is it to remove and replace the bellows? What is the proper procedure? (I think I can get to some of them without removing the dash.)

[zadefaraj]

Awesome! Well.. not the problem, but at least you've narrowed it down.

Let's see.. the way I replaced the bellows was by first taking them off of whatever they are attatched to via a clip. The clip should be on the backside, and i beleive the bellows slide UP to come out. Then, once the bellow was detatched, I proceeded to remove the metal arm that connects it to the flap (from the bellow side). I did this by pretty much peeling it off like distribution block thing. ie: rotating the billow to kind of 'pop' it off the lever. 'like a bottle opener'.

Now with the bellow just connected to the vacuum line, if I recall correctly, i stuck mini screwdrivers or something small around the opening to pry the locking mechanism open and get the vacuum line out. I beleive the lines we're held in place this way.

Replacing it is easier, and you should be able to follow the same procedure in reverse order.

If it takes some time, dont get too frustrated, even if you can see them, they are still quite difficult to work with.

Also, if you find that number 352 is one that is bad, and number 154 (the center vent controller), try replacing number 154 first. If you can reach it without removing the dash, maybe you might be interested in just sealing the number 352 line. If you get the cenver vent bellow replaced, try covering the number 352 line with your finger from the distribution block end and see what happens when you change the vent positions.

Also, for some reason, and this might make your task easier, sometimes 2 lines found at the distribution block connect to only 1 billow. Best way to find out is to write down the colors of the lines that are bad, and try and trace them. Some are easier to find than others, but like I said, number 352 is just stupid. If you can reach, play around the the metal arms to see what they control, but be careful, their edges are like razors!

keep me posted

zade

[htfan1]

I appreciate your encouagement.

I'm going to try a workaround first by just plugging the 3 bad lines on the vent vacuum module. I'll find some rubber cap that will do the job and not damage the unit.

If the vent control is then somewhat functional with 5 of the 8 working, I'll make the decision to replace bellows or not.

By the way, where did you purchase your replacement bellows?

I'll continue and keep you updated.

Jeff

[zadefaraj]

Sounds good! I got mine from one the local dealerships in Houston; Star Motor Cars. I find most of their prices reasonably fair, and sometimes 70% cheaper than the other Mercedes dealership in town. I think I purchased mine for about $60~80 each.

http://www.starmotorcars.mercedescen...iceparts.jhtml

Good luck!

zade

[htfan1]

The test is going GREAT so far! I have plugged line #2, #4 & #8. The funny thing is the vents still seem to be "mostly" working properly.

I purchased some small plastic screw tip protectors from a local harware store. (The type normally used to cover the sharp ends of screws protruding through material.) These screw protectors fit PERFECTLY over the vacuum line ports on the vent/vacuum control module.

NO more vacuum whrring noise! I still have required control over critical vents. The only issue is the center vent will stop working from time to time ONLY when A/C is on. If I'm not using A/C, the center vent works fine.

I'm still in test mode, but this is a much, much better situation then before!!!! I'll keep you updated.

[crit1]

The link to the dashboard removal does not work for me. Can someone repost a functional link please? Thanks.

[crit1]

Never mind. I found it. Thanks a bunch.

[alphanumeric]

crap the link doesn't work? how did you find it? I really need to get around to doing this to my car someday lol

[zadefaraj]

http://www.zadefaraj.com/dashboard.htm

[nick_nolastname]

Once again thanks for posting such a detailed guide.

I realize this thread has not been touched in quite some time, but I'll bet people view it quite a bit.

For people that have a problem with just the center vents, like I do, I'd like to share what I did to solve the problem.

1) Remove the passenger side footwell cover on the bottom of the dash. You have to turn the phillips on the black vent 1/4 turn CCW and pull that out, then remove the three phillips holding the cover in place. Now remove it.

2) You will see two vacuum modules underneath, that have metal levers going up into the dashboard. These control the center vents. If yours are leaking and the pump keeps running, disconnect the vacuum lines to them and block them off so it wont leak any more.

3) Now using a long tool like a 12" pair of hemostats, reach up in there and pull the metal rods off the plastic cranks that control the vent doors. Now, just turn the vents to open and they will stay that way! If you ever need to turn them off, use the wheel on the front of the vent like you normally would. Voila! Problem solved. Why would you want to put another vacuum module in anyway if they are such peices of crap? Its a bad system. Thats the way it is.

Also, another thing I discovered today; my blower had a squeaky noise/clicking noise that was most noticable at low speeds. I figured some pine needles or something had gotten stuck in there, but I was wrong. The motor sits on two rubber cushion things that had settled a bit, and the rotor part was rubbing ever so slightly against the base of the blower housing. I took out the two screws that hold the moter into its housing, dremalled off the washers, and inserted two new washers ABOVE the rubber mounts, to increase the rotor to housing clearance by 1mm. Now its as quiet as the day it was made.

Good luck.

[OzC36]

Good write-up...thanks Nick!

[OCKlasse]

Can't wait to try this thank you!

[OCKlasse]

2) You will see two vacuum modules underneath, that have metal levers going up into the dashboard. These control the center vents. If yours are leaking and the pump keeps running, disconnect the vacuum lines to them and block them off so it wont leak any more.

Hey, so what did you do to "block off" the vacuum lines?

[nick_nolastname]

Silicon sealer.

I dabbed a bit on, then let it dry before starting the car back up. I didnt want it to get sucked up the line while still soft.

If you care about not having to pick it all off to use the lines again someday you will probably want to choose another option. This is my permanent repair so I dont care about that. Perhaps there is a joining piece you could get from MB that would allow you to connect the two vent lines together.

[OCKlasse]

Originally posted by nick_nolastname
Silicon sealer.

I dabbed a bit on, then let it dry before starting the car back up. I didnt want it to get sucked up the line while still soft.

If you care about not having to pick it all off to use the lines again someday you will probably want to choose another option. This is my permanent repair so I dont care about that. Perhaps there is a joining piece you could get from MB that would allow you to connect the two vent lines together.

Any way you'd be bored enough one day to take a pic in there?

[nick_nolastname]

I would... does this site host pictures? I dont see how to do it.

I really feel for people who own these cars and I do want to help.
Two days ago I used the guide someone posted here to help me remove my roofliner to get it redone. We can really help each other out.

But I dont see how to upload a picture here. Help me out if Im missing something.

The two modules in question are near the center part of the dash that runs between driver and passenger, and they have vacuum lines running to them on their bottoms. You remove these and block them off at their little connections on the tubes. On the top, aluminum rods reach up into the dash and attach to black plastic levers that move the vents. You really cant miss it if you just get in there and look. Its difficult to get under there and look up if you arent physically fit I understand, but you can also just take a bright flashlight and a mirror from your wife's makeup desk and look up there that way while being comfortably upright.

Good luck.

[OCKlasse]

Originally posted by nick_nolastname
I would... does this site host pictures? I dont see how to do it.

I really feel for people who own these cars and I do want to help.
Two days ago I used the guide someone posted here to help me remove my roofliner to get it redone. We can really help each other out.

But I dont see how to upload a picture here. Help me out if Im missing something.

The two modules in question are near the center part of the dash that runs between driver and passenger, and they have vacuum lines running to them on their bottoms. You remove these and block them off at their little connections on the tubes. On the top, aluminum rods reach up into the dash and attach to black plastic levers that move the vents. You really cant miss it if you just get in there and look. Its difficult to get under there and look up if you arent physically fit I understand, but you can also just take a bright flashlight and a mirror from your wife's makeup desk and look up there that way while being comfortably upright.

Good luck.

Thanks Nick. I'm a fit 22 year old, so I hope I can get the job done!

[OCKlasse]

OK, so I have two pics for you and two questions

First, is it these four vacuum lines that I want to remove and block? Any specials tricks you used? These things are on there tight!



Second, how exactly did you go about removing the levers? From the top I assume? Once they are removed, do you then physically move the vents with the pliars, or hemostats as you suggested? Thanks



Just don't want to screw anything up

[nick_nolastname]

Nice!

Those top two vacuum lines are the ones I removed, the ones going to the grey vacuum modules. Pull straight down on those light gray plugs that are the ends of the hose. They are on tight but they do pull right off. I promise. Think German! Those other two lower ones... I dont know where they go. You have to remember you aren't talking to a pro here, just a cheap hacker trying to keep his wife happy with this stupid car. This advice is worth no more than you paid for it, my friend!

Those two aluminum rods go up in there and are press fitted over a barb sort of fitting ( one for each rod ) that holds them to the black levers that control the center vents. I used a pair of 12" hemostats to reach up there and kind of twist them off the barbs. Then once removed, I used the hemos to turn the vents to the open position, where they will stay quite willingly. Try pulling down on those aluminum rods while looking up in there and you will see how it operates. If you are uncomfortable ripping that mechanism apart, you might be able to to just pull the levers down and secure them somehow without disconnecting them. I found that to be impractical because on my car, the springs forcing them up to the closed position are absurdly strong. Maybe yours will be different.

All in all a right bitch to get to based on their position and how you have to hold your body to get your arms in there.

Best of luck.

[OzC36]

Those top two vacuum lines are the ones I removed, the ones going to the grey vacuum modules. Pull straight down on those light gray plugs that are the ends of the hose. They are on tight but they do pull right off. I promise. Think German!

nick-n-l-n
Just for clarity, did you:

1. Pull the vacuum tubes off of the terminating grey fitting; or
2. Pull the grey terminating fitting from the darker grey modules?

[nick_nolastname]

I pulled the light gray fittings off of the vacuum modules. I did not disconnect the hoses from the light gray fittings.

[OCKlasse]

Well, I did it! Thank you to Nick for all of the help!

I disconnected the right pair of vacuum lines, (the other left ones control the module for getting air to the footwell area) then gave them a nice treatment of silicon sealant.

Once that was done, the vacuum modules actually dislocate fairly easy. I was then able to get a long, thin flathead up there and disconnect the end of the metal rod from the plastic unit. You just push the top of the levels to the left as it is slid over a plastic rod. I then pulled the two modules out altogether. A little tonsil-work for the 202...

After that, move the plastic levers controlling the units all the way DOWN, and recover everything!

I now get tons of air blowing through the center vents! Once again, Nick is the man! :bunny:

[OCKlasse]

Originally posted by nick_nolastname
I pulled the light gray fittings off of the vacuum modules. I did not disconnect the hoses from the light gray fittings.

This is what I did. You'll find it practically impossible to do it the other way without damaging the vacuum line.

[nick_nolastname]

Rock on! Glad to be of help.

[OCKlasse]

Alright, so now air comes out of the center vents, as does AC, but not heat. I will have heat coming out of the side vents, but cool air will still blow through the center vents. Any ideas?