Hey guys I have a 300 SDL 1987....The door locks I noticed recently when unlocking the doors at the drivers side the rest of the locks wont go up...but when i get into the car I hear a buzzing in the back seat area...maybe trunk that sounds like a car antenna trying to go up but its stuck...then after 15 secs it stops...I know this is related to the locks how do I fix this...

Chris

I'm not sure where the pump is in the '87, it is in the trunk next to the spare in the '91. Anyway, if a line breaks somewhere, the pump will run and do nothing.

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Gone to the dark side

- Jeff

Sounds like a vacuum problem. So you have a hole in one of the vacuum lines, line disconnected(seen it) or a bad supply pump. Also you may have holes in the Y connectors. Also the vacuum actuators in the door mabye faulty

AS for the sound do you have anything on?

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

nope...just after I unlock and sit in the car...I hear the noise for about 15 secs


Where are these lines at?

bump

Usually under the carpets and in the doors.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

are any of the vaccum connections start under the hood cause I have a few deteriorates vaccum lines I can see in there...

The vac lines under the hood have nothing to do with the locks. Open up the channel on the right side of the passenger floor; plug your mityvac in there to each vac line one at a time and determine where you have no vacuum. Then trace that line. You may have to replace a door lock actuator or just a rubber connector - or you might need to replace the pump. Sounds like the pump may be OK. I replaced two door actuators in my 300SD and all the locks work again.

Where is the pump located at?

If it's at all like most of the rest of the w126 cars, the pump is located in the spare tire well, just to the right rear of the tire itself. Most likely it is covered by a metal guard plate, and cocooned in a foam "football".

The vacuum plumbing on my cars is located along the right floorboard, near the door sill. To get to it, you have to lift the carpet up, and then the edge of the plastic cover that guards the wiring and plumbing along the floor.

The fastest point I found to test for leaks was to disconnect the line coming from the pump at the junction where it hits the fuel door lock, just behind the trunk carpet on the right side. I hooked up a vacuum gauge to watch the needle swing.

Best of luck, and happy plumbing! :p

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-Josh
Testing the cheap Mercedes axiom, one bolt at a time...

Would a vacuum problem like this also cause door to not open at all? The rear passenger door on my 300TD has stopped unlocking. Just prior to that, however it would not open even when unlocked. At least it appeared to be unlocked.

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

Vacuum lines are underneath the carpet and go into the doors. The only problem with w126 carpeting is that is 1 piece unlike the w123.

There are Y connectors in the front both passenger and driver side underneath the carpeting area which have the vacuum lines that go to the rear doors.

In some cases I have seen them completetly disconnected on cars to having cracks in the Y connectors and the door actuator not hold vacuum

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

If the unlocking mechanism stuck in the locked position, then yes. It could also be that the linkage became disconnected.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Is an "actuator" the same as an "element"?

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I never go far without a little Big Star

1994 E500 199/Gray 82k
84 300D (Salty) Orient Red/Palomino 141k
88 300CE (Ersatzhammer) 904/Java 163k -- Turbo Technics twin turbo kit, AMG Gen I body kit, Sportline steering box and steering wheel, Sportline/Eibach /Bilstein Sport/500E suspension, Quaife LSD in 210 mm diff case, Silver Arrow brakes.
88 300CE Brabus 3.6 199 on Black 44k

The actuator is a blue (original) or black (new) plastic device with 1) a connection for the vacuum hose and 2) a connector to a push rod which locks/unlocks. Not sure what an element is.