vaccum lock question - PeachParts Mercedes-Benz Forum

TheDon · #1 11-20-2005, 12:37 PM

ok my locks dont work like a majority of 20 year old mercedes but i was sitting in my car with it off doors closed and pushed the lock thing down and the rest followed.. then when they were all down i lifted it up and they all followed half sec later and i could hear a noise coming from the rear trunk area ish. so my system doesnt leak if it can go up and down with no problem but i cant lock and unlock with the key.. shed some insight

also how hard is it to remove the valve cover on the 85 300D engine.. i dont know the engine code like my last cars.. mitsu 4g63t etc etc

Rick Miley · #2 11-20-2005, 01:12 PM

The vacuum operated locks are activated only by the driver's door. Although you can lock and unlock the passenger's door and trunk with the key, the rest of the locks will not follow. Furthermore, there is an interlock on Mercedes doors that prevents locking them while they are open. This is to keep you from locking your keys in the car. So are you saying that if you close the driver's door and lock it with the key, the rest of the locks don't follow?

The valve cover is not a big deal. Remove as much accelerator linkage as necessary, along with whatever vacuum stuff is on top. Then remove the mounting nuts and the cover lifts right off.

TheDon · #3 11-20-2005, 01:23 PM

i know about the interlock thing on the drivers door but if your vaccume locks dont work shouldnt you be able to lock and unlock with just the key? because i cant lock/unlock with the key my car is in my driveway unlocked becuase if i lock it i cant get in it.. and dont bother stealing anything out of it.. nothing special

Rick Miley · #4 11-20-2005, 01:25 PM

If you can't lock the driver's door with the key (when it is closed) then that's a mechanical problem with the lock. Not anything to do with the vacuum.

TheDon · #5 11-20-2005, 01:29 PM

i locked the doors and left the window open and the passenger door wouldnt unlock either. also the fuel door doesnt lock

kerry · #6 11-20-2005, 02:01 PM

Someone put in a different ignition switch so the ignition key no longer works for the doors??????
Does it work on the trunk?

TheDon · #7 11-20-2005, 02:06 PM

it works on the trunk i tested that it locks unlocks the trunk no problem

also i dont have the supplement key only the master key which is a reproduction not original

Rick Miley · #8 11-20-2005, 02:09 PM

And does it work on the glove box? I think a good place to start would be to order a genuine VIN cut key from the dealer.

TheDon · #9 11-20-2005, 02:10 PM

i suppose it would be.. ill call and get prices.. xmas is coming lol. i really dont care if the vaccum locks dont work but as long as i can lock the car with a key im happy

Rick Miley · #10 11-20-2005, 02:13 PM

Open the driver's window, close the door and, from the ouside, lock the door with the plunger. Then check the trunk and fuel filler. Are they locked? Unlock the driver's door and check everything again. Are they all unlocked? If so, you have no vacuum problems. Just key problems.

TheDon · #11 11-20-2005, 02:26 PM

i turned the car on and let it sit for a minute to build vacume so i can fool with the locks.. window open i locked it.. the rest followed couple seconds late.. unlocked.. rest followed a lil late.. locked it and trunk was locked fuel door open.. unlock.. trunk still locked fuel door open took key out of ignition and it shuts off no problem... so im guessing vaccume problem along with key issues

Rick Miley · #12 11-20-2005, 02:32 PM

Ok, it sounds like the vacuum element for the fuel door may be leaking. That one and the one for the trunk are not as robust as the ones for the doors. But I still thing you should start by fixing the key problem.

TheDon · #13 11-20-2005, 02:34 PM

ok sounds like ill do the keys first then get a mity vac and test the trunk and fuel door elements