simark13

the trunk wont lock at all, the doors can all be locked manually except the drivers door, when i push both locks down in the rear, the locks in the front go up and vis-versa.. weird. annoying because i cant leave anything in the car. what could this be?

philip29

hey all your locks are control by a vacuum pump system that is located under the backseats on the passage side it will have air line running from it, if it stop'd workin them all your locks will not work because the locking system relies on the vacuum pump to pull air into the pump to lock the doors and to push air in the locks to unlock your car includes your trunk.. you car go to benzworld.org , under the w140 section and ask the members there and they have pics and diygrams to solve your problem.

simark13

excellent, unfortunately i have already gone to mercedes benz of chicago and paid to have it checked.... so and they think the vacuum pump u are talking about is causing a couple of fuses to blow out and told me i should get a new pump and that hopefully that is what is causing the problem, however the pump is $1700. i did look on ebay and found some used ones for $200, but idk if i can rely on them... whats your thought on that?

philip29

There is a brand new vaccum pump on ebay for 349.95 with warranty the item number is 230545567195 i would go with that option instead of buy 1,700 pump from the dealer.. because they have to up there prices to make money off of the part..and plus it's a dealer..

Peter Guenther

The pumps are avaiable from various vendors as "rebuilt", with Ebay you never know.
http://catalog.peachparts.com/
http://germanstar.net/Mercedes_Parts_Catalog.html

benica

While the prices are good....they are not new in my opinion.....why sell a 1500 dollar part for 3-4 hundred bucks?
These are refurbished I think.
But hey...as long as they work and offer a warranty...I'd get one!
'cept I do happen to have a brand new OEM in the unopened box from the dealer! Had it for a few years for a back up when the one in the car stops.

simark13

thanks guys for your insight, im not gonna take care of it just yet, i've only had the car a couple of weeks and the holidays had me spending a lot of money. but maybe next month i'll get the pump (not from the dealership), and i'll go from there. i'll post how it goes

ramblinche81

I bought my NEW Bosch oem pump on ebay for $350

NihalS65

before you get a new pump see this link, you can prolly troubleshoot it yourself http://w140repair.com/Closing_Assist_Pump.htm

I also live in chicago, which mechanic did you take it to? I have a great merc mechanic who is honest and wont rip you off. I had a annoying noise in my suspension and mercedes of westmont wanted me to shell out $1800. i paid my guy $90 and he fixed it for good.

i have a similiar lock problem...only mine is that the rear doors dont lock or unlock unless done manually. the trunk and front doors work fine however. any suggestions?

Peter Guenther

All the actuators are on the same line, if you have an old style pump they plug into a plenum, if you have a new style there is a six port "t". There is a tool called "mighty-vac" which will alow you to draw a vacuum and see if it holds. Its pressure to unlock and vacuum to lock

simark13

hey nihals65, thanks for the info, i'll have to get in touch with your mechanic when i'm ready to fix the problem... right now i have to focus on fixing my nissan because it's due for an emissions test in a couple of months and the check engine light is on.