Suzdalov

"Closing aid system" that sucks in the door when you close it always needs to be reset on my car for some reason. I close the door and it sucks it in........then after a few times it stops and I have to slam the door real hard to get it closed. I pull out the break for "closing aid system" that seems to reset it......and it works again for a couple of days and then stops again. Another strange thing is that if driver door stoped closing all other doors still would............then after some time the other doors would stop automatically closing. I assume that there either a vacum leak or vacum pump is dieing.

Any suggestions ................I took it to a dealer ...........no codes that could correspond with this proble............

Any Ideas ...Guys...

rhgtara

99% certain you will have to replace the pump located in the trunk over the left wheel well.

guydewdney

99% certain that you have a leak.. the pump shuts down if it cant attain the correct PRESSURE (its +ve pressure not a vacuum) after a certain time - there is a thread on here somewhere about adjusting the timeout pressure - try a search?

dlafever

I vote for having a leak and needing a new pump, ususally the first followed by the second.

tyzik

Common problem, check for leaks....might need a new pump 2.....

brett san diego

You may have a minor air leak. Most likely, all you need to do is turn down your pump's shut-off pressure. See my post on that other MB forum, www.mbnz.org (Benzworld). Search the W140 forum for "Getting to know your closing assist pump". Or just look for my post in the "knowledge base" thread which is stickied and always shows up at the top of the page. My username there is the same, Brett San Diego.

Here's a link to the post, if it works:

http://www.mbnz.org/forums/forums/th...id=13#M1466979

good luck,
Brett

Suzdalov

I reduced my shut off pressure and it got a little better................mean I didn't have to pull out the fuse #9 as often................and now it's back to the same............I have to pull out the fuse to reset it a couple of times a day..........it doesn't seem as it's an air leak 'cos then it would shut off that only line that leaked and the other doors would still work I assume...............but eventually it shuts off all the doors and the trunk in the order that the doors are used the most get shut off first.

Peter Guenther

I am on my second pump, and they found no leaks when they replaced it at N/C. Finding a leak would have given them reason to charge something. It is easy to check the system for leaks, a Mighty Vac tool will create a vacuum and the guage will tell if it leaks down. From what I know there is both a timing and pressure/ vacuum safety. I know the locking pump has it!

Suzdalov

So did you figure your problem........................does you close assist work all the time now....................

Peter Guenther

I went thru the same thing in 96, the trunk would not pull down, then one of the doors would not close. I checked with Mercedes and aftet telling me the pump is common failure they suggested the pulling fuse thing. I got tired of that and spent the $700 it acted up a few days later and they did the trunk handle mod since there was a service bulletin at N/C. It worked fine they did nothing but replace the closing assist pump. I asked for it and opened it up, lots of stuff in there. I kept it for a while and then during one bench cleaning it went in the trash. My friend at MB in Chicago told me a lot of mechanics keep the pump since there are people buying them to rebuild. There were no problems for 5 years, then one of the doors acted up. I had become a close friend with the shop forman at my local dealer (my ML was a piece of crap)and was in at least once a month. He suggested they look at it, they checked out the vacuum lines, replaced the pump, and it has been fine. They did this in a car that was 10 years old the pump at least four years since being replaced the last time and did it at N/C. The factory rep claimed it was "good will" and patience with my ML, this was in Jan of 02.
There is some thought out there that the lock mech might get stiff and the pump goes in to the safety failure, that is what you reset when you pull the fuse. In both of my issues a new pump fixed it, one only for a five years, the second who knows

SAMM

GUYS I HAVE THE EXACT SAME THING. I PULL THE FUSE AND THE DOORS SUCK IN FOR ABOUT 4 OR 5 TIMES THEN STOPS. I CAN HEAR THE DOORS BEING SUCKED IN AT TOO HIGH A STRENGTH. I HEAR IT PULLING FOR QUITE A FEW SECONDS AFTER THE DOOR IF FULLY SUCKED IN. I DO NOT KNOW IF THIS WHAT YOU HAVE EXPERIENCED EXACTLY?

ANOTHER POINT IS THAT MY PUMP IS NOT IN EITHER SIDE OF THE INSIDE LAYER OF THE TRUNK. ON THE LEFT THERE IS THE SUNROOF MOTOR ONLY. ON THE RIGHT THERE ARE ELECTRICAL FUSES/RELAYS AND ALARM RELATED ITEMS. WHERE IS THE VACUUM PUMP FOR THE DOORS?

IS IT UNDER THE REAR SEATS? HAS ANYONE GOT THIS THING IN A PLACE OTHER THAN THE TRUNK?


I REALLY WOULD LIKE TO FIX THIS SILLY PROBLEM. IT IS WORTH NOTING THAT THE DRIVERS DOOR DOES NOT SUCK IN AT ALL AT ANY TIME. FUSE PULLED OR NOT.


MUCH OBLIGED TO YOU ALL

syljua

Hello,

Look at this;

http://www.classic-roadster.de/cgi-b...=&ITEM=M14%2F3

for the pump location. (and please turn caps-lock off:-)

br,
syljua

Peter Guenther

The close assist pump is over the drivers side rear wheel and is best gotten to by removing the liner in the fender and the one covering the gas tank and rear speakers. The lock and unlock pump is under the passenger side rear seat in a foam enclosure

SAMM

syljua and peter thank you kindly for helping with that point. I took the inner lining off 3 times without realising that I had to take all of the lining off the back of the trunk inner lining

syljua that web page was most helpful, now I know where to look.

Much appreciated

Peter Guenther

As I said before the pump gets a signal to start, It then produces pressure to draw in the door. If it reaches its pressure point before getting a closure from the microswitch it will time out, if it sees two of those failures it will disable that circuit. This could be caused by dry linkage in the lock, it could be cased by a dirty microswitch, it could be caused by a pressure switch in the pump loosing its setting, and it could be caused by the timing circuit in the pump. I
noticed the doors draw in so slightly beyond locking and then relax as the pressure is relived and vacuum is sent down the line to reset the diaphram. In both my failures repacing the pump cured it, for approximately 5 years and no other items were replaced/repaired other than a trunk lock was replaced when the first pump failed, there was a service bulletin on it. The service bulletin removed the handle retraction from the lock and unlock pump (pse)which has never failed, to the closing assist pump? Go figure!

Suzdalov

So i got my car back from the dealer and they said the pump need to be replaced.........$1185.00 my god...................They said that they've tested all the lines for vacuum leak and there was none. .................So, they just said after a certain time the pump just goes bad and it might still work with the fuse # 9 for a little but the system will kick it out more and more often.........and that eventyally the pump still has to be replaced.................................they've chrged me $375 to test all this crap and tell me that my pump is dying ..............bustads..........so in my case it seems like I need a new pump...................

BenzKid24

damn......thats crazy...its really a "luxury" feature and you can save that type of money for something that is NEEDED for the car to run right,plus i heard thoses pumps never stay working,even after there new,due to the doors being so heavy.

cscheat

Definately NEED A NEW PUMP!!!!!!!!!!!!!

Peter Guenther

You can get the pump cheaper than that, and replace yourself. I would definately get a new one from a reputable source, not that crap on E bay.
As you noticed it can work for a while after repowering and why would anyone have an extra. I am on my second, the dealer could find nothing leaking either time. About five years between failures!

Suzdalov

Ok, got sick of slamming the doors all the time to get them closed. Went and reduced the shut off pressure again even more, and cleaned the pump with pressure air, now it works for a couple of days before I have to pull out the fuse # 9. Still annoying that it has to be pulled out every two, three days, but at least the door closes, 'cos it was starting to get all loose the door covers from slamming it every time. Will leave it at that for now. Cant really blow $500 on a new pump right now. I actually have another problem..............i broke off my passenger side mirror.......and it's over $1000 at the dealer......................jesus ..............crazy or what..................going to fis the old one with fiber glass and just repaint it. It's not gonna fold with a press of a botton but who cares..........it's 200 instead of a 1000 at my buddy's garage.