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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #1
so i am disassembling my close assist pump to try and figure out what its issue is, but i cannot get the diaphram disconnected from the main air line that goes to all of the selenoids because of the little clip that connects them. i cannot get it to let go for the life of me. i have tried to pry each side apart with no luck, and i have tried just to slide it apart with no luck. any ideas of how to get it apart without breaking it? Thanks in advance :)
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #2
and now i have another question. why is there the one line that is hooked up to nothing? what purpose does it serve? i only ask because upon observing my pump a little more, i have realized that the line that is hooked up to nothing is not closing, and thus letting air out and not closing the door. so what would happen if i just blocked it, or closed it?
 

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1998 140.070 CL500, 1966 406.121 U65
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1,463 Posts
and now i have another question. why is there the one line that is hooked up to nothing? what purpose does it serve?
It's there to vent out moist that form in the line when the motor creates pressure
in the lines. Its the one thats on its own, right?;



(image from coupe version)

Heres an image of the difference internally;



Do not block it. It should be free to vent out.

br,
syljua
 

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1992 600SEL and 1990 ford taurus GL
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270 Posts
Discussion Starter #4
sorry for the delay, but i finally did get my pump in perfect working order!!!! =DDDDDD turns out that the solenoid for the outlet line is actually dead, and that's why I was asking if it would be possible to just clog it. what i originally did was just ghetto rig it by putting a ear plug into the outlet line. ( see pic lol ). it worked quite well, it sealed so the pump could close the door, and absorbs moisture so that moisture isn't trapped in the lines. i then pulled the plug out so that i could put it all back together, and in doing so i actually pulled the solenoid out to the closed position. this sealed the pump so it works perfectly well now. even though the solenoid is dead, it works because it's just the outlet line. i think that if the system was made up of metal tubes or had more metal components, moisture would be more of an issue, but where it's all plastic, i don't think it will be an issue.
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #5
and now i have another question :D all of my DOORS self close, but my trunk does not. i know that there is some sort of leaver that turns the trunk lid from either self close, or manual close, it was in my owner's manual. and since the close assist has never worked before, ill bet that it's in the manual position. my question is how do i switch it back? i think that it's something mechanical, but idk. i do know that when i open the trunk i hear the pump run, and the little latch on the lid itself pulls it self in until the pump hits the appropriate pressure and turns off. but if set the lid closed, it don't do nothin. i tried switching them without anything changing or being different. ill post some pics to show you the levers im talking about.
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #6
ok and so before i retire for the night i came up with another question for the people who do have working self closing trunks. do you still have to kinda slam the trunk closed, and then the close assist takes it from there? or do you just set it there, like one of the doors, and then it closes? and what part of the trunk latch system moves? the latch on the lid it self or the latch just above the lock key hole? on all the vids i've see of the trunks self closing, the user has to slam it, then the close assist takes it from there. like these:

- fast forward to 5:25

- fast forward to 2:17

- this one is weird, the guy does something, and then it closes...
 

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1997 S600 (sold)
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4,660 Posts
You have an earlier generation car than mine so things could be different. There are some known differences specifically at the trunk latch on early models. But, on my 1997 model, the central locking pump is responsible for releasing the trunk striker eye in the trunk lid when the trunk is opened so that it is ready to be pulled back in when the trunk is closed. It is the eye in the trunk lid that gets retracted into the trunk lid mechanism. When I started to fix my system, I found the previous owner had disconnected and plugged the air line from the central locking pump to the striker eye release actuator. When the striker eye is then set for manual closing, the setting is permanent because the striker eye never gets released by the action of the central locking pump.

You also need to check the location of the lower latch in the body and make sure it is not too low, which would require you to really slam the trunk to get it to latch if the striker eye is set for manual closing. It's just a couple of 10 mm bolts on either side of the latch to move it up and down.

Brett
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #8
You have an earlier generation car than mine so things could be different. There are some known differences specifically at the trunk latch on early models. But, on my 1997 model, the central locking pump is responsible for releasing the trunk striker eye in the trunk lid when the trunk is opened so that it is ready to be pulled back in when the trunk is closed. It is the eye in the trunk lid that gets retracted into the trunk lid mechanism. When I started to fix my system, I found the previous owner had disconnected and plugged the air line from the central locking pump to the striker eye release actuator. When the striker eye is then set for manual closing, the setting is permanent because the striker eye never gets released by the action of the central locking pump.

You also need to check the location of the lower latch in the body and make sure it is not too low, which would require you to really slam the trunk to get it to latch if the striker eye is set for manual closing. It's just a couple of 10 mm bolts on either side of the latch to move it up and down.

Brett
ok, so then you have to slam the trunk closed, and then the closing system takes it from there right? you don't just set it there?. because right now i don't have to slam the trunk lid hard, but i have to close it like a regular door without closing assist.

so should i take the lining on the trunk lid off to see if i could find anything that your describing? and if so how do i do that? is it the same as the regular trunk lining? just a bunch of little clips that you pull out?
 

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1997 S600 (sold)
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No, you don't normally have to slam the trunk. You have to close it hard enough to cause the striker eye to operate the lower latch, then the closing assist takes it the rest of the way closed.

You can observe the action of the striker eye mechanism with your own eyes. Open the trunk, then simulate trunk closing by rotating the catch in the lower latch with your thumb. You should observe the trunk lights going out, the trunk handle retracting, and the striker eye retracting. Then, "open" the trunk by either using your remote or manually pushing the lock. You should observe the lights coming back on, the trunk handle extending, and also the striker eye releasing. If the striker eye does not release, then I would begin by taking off the trunk lid liner and inspecting air lines and connections. It's been a while since I removed mine. If you don't see any of the black plastic "push rivet" fasteners to remove, then it's just the usual hidden plastic clips like door panels. Just pull to release the panel.

Brett
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #10
No, you don't normally have to slam the trunk. You have to close it hard enough to cause the striker eye to operate the lower latch, then the closing assist takes it the rest of the way closed.

You can observe the action of the striker eye mechanism with your own eyes. Open the trunk, then simulate trunk closing by rotating the catch in the lower latch with your thumb. You should observe the trunk lights going out, the trunk handle retracting, and the striker eye retracting. Then, "open" the trunk by either using your remote or manually pushing the lock. You should observe the lights coming back on, the trunk handle extending, and also the striker eye releasing. If the striker eye does not release, then I would begin by taking off the trunk lid liner and inspecting air lines and connections. It's been a while since I removed mine. If you don't see any of the black plastic "push rivet" fasteners to remove, then it's just the usual hidden plastic clips like door panels. Just pull to release the panel.

Brett
so to make the trunk soft close, all that has to happen is the striker eye has to make contact with the latch, and then it will close? does the actual latch move at all?, or is it completely manual? because when i push the lock to open my trunk (the older models don't have a button lol), the handle pops out, the trunk lights come on, and i hear the close assist pump start, and i can see the striker eye retract in. then the pump hits its shut off pressure and it shuts off. but the latch doesn't do anything at all, i think its just manual. then if i push the latch closed, as if the trunk lid pushed it, like you say the lights go out, the handle goes back in, but i never hear the pump activate, and the striker eye does not move. maybe someone hooked up something electrical incorrectly?

Would you be able to make video of this happening all in action? i would like to see what a correctly working system does.
 

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1997 S600 (sold)
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4,660 Posts
Yeah, that's backwards. The striker eye should extend not retract when you open the trunk. It should extend about 1/2 inch. It's not a slow extension. It literally pops out really fast under spring tension.

It sounds like what others have described when they have a mismatch in components. As I mentioned, the earliest models had a different trunk striker eye mechanism, and there was also a different pump with one additional pin in the connector.

Here's a definitive post on this matter, but unfortunately nubyOz doesn't post a final result on what he did:

http://www.benzworld.org/forums/w140-s-class/1388220-trunk-close-assist-3.html#post3475538

At some point (not sure exactly when but I think around 1994), the factory changed the design, and also dealerships had a retrofit kit to make updates to old cars. So you need to know the history of your trunk latch to know exactly where you stand. You may have the original latch and a newer pump, or old pump and new latch. Unfortunately, I cannot give you guidance on what to look for to know whether your striker eye mechanism has been updated or not. I have never seen the old mechanism to be able to compare to my car. But that post above has some part numbers to help you ID things. The newer pump has one less pin in the connector as shown by nubyOz.

If you take off the trunk lid liner, you can use a screwdriver or other prying tool to manually operate the striker eye release lever and observe the extension of the striker eye. Then you can watch it get pulled back in by the pump (unfortunately in your case when you open the trunk rather than when you close it).

Brett
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #12
thanks for the link, it gave me a bit more info, and therefore a bit closer to solving my issue :)

but i do know that my connector on my close assist pump has all ten pins, not eight or nine. I think that my car is actually a 1991 1/2, instead of a 1992, because of the ten pins on the connection for the close assist pump, and the fact that my odometer is still a mechanical system instead of a digital display.

ill have to check out my system when i get a chance, but im guessing that the pse pump does not play a role in closing the trunk at all.

any idea what the little yellow leaver does that's near the latch? from what i looked at, it does nothing that i can see so far
 

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1992 600SEL and 1990 ford taurus GL
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Discussion Starter #13
ill have to check out my system when i get a chance, but im guessing that the pse pump does not play a role in closing the trunk at all.

any idea what the little yellow leaver does that's near the latch? from what i looked at, it does nothing that i can see so far
ok so disregard both of these just read the rest of the article :)
 
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