Trunk stuck closed HELP 1979 350SE

[mercedes350se]

A couple nights ago I went to open my trunk and it wont open. It was working fine before and just happened suddenly. If I push the lock to open the trunk it just goes in and gets stuck. In order to have the lock button release back out I have to put the key in the lock and lock it and it pops back out. But if I try to open it again the same thing happens with it getting stuck after being pushed in. I'm not sure what the problem is but I read that it may have to do with the vacuum system for the locks. Can any one help me figure out how to fix this? Its been bugging me for days now  Any help is appreciated! Thanks!

[revilla]

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[revilla]

sorry, posted wrong message

[rumb]

Are you saying you are unable to open the trunk lid despite fiddling with the key?

Using the key can you find a spot where it will open the trunk?

Either the vacuum pod  is bad, or the lock assy is loose where it mounts.  Either way you need to get the lid open to fix.

My car came with a 1" hole drilled behind the license plate area  so the PO could fish in there to open it. of course as I found out recently there were no keys that fit the trunk lock which may have played into it.  Are the rest of the locks working correctly with vacuum?  including the gas tank door?

[s class]

What you can do is :

- remove rear seat
- open cable tray running up right bulkhead
- access the two vac lines
- cut into the vac line and use a vacuum pump to suck on it, to set the trunk lock to the 'unlocked' position
- (you might have to try both vac lines - one is for 'lock', the other for 'unlock')

[mercedes350se]

What you can do is :

- remove rear seat
- open cable tray running up right bulkhead
- access the two vac lines
- cut into the vac line and use a vacuum pump to suck on it, to set the trunk lock to the 'unlocked' position
- (you might have to try both vac lines - one is for 'lock', the other for 'unlock')

So when I pull the seats out are there any other vacuum lines or hoses that I should be careful not to cut into? And after I cut the lines, I will have to replace the lines? Or is it that they just pull off a nipple or something like it? I read somewhere that the vacuum line is under the passenger carpet? Last question, I also noticed that the door locks are slow to unlock and lock. I assume this is a vacuum issue as well so is there a way to see the vacuum lines for all the locks (trunk and door locks)? Sorry for all the questions I am just a little lost. Thanks for all the help much appreciated!!

[ptashek]

Vacuum lines for the rear doors, the trunk and fuel cap locks are running along the side members, under the carpeting. Front doors go under the dash, and through the cable channels.
This is a layout forW123, but the W116 should be identical for the most part: http://i.imgur.com/YV8Dj5M.jpg

You're interested in the red line.
It's more likely to be yellow, with red stripe and yellow, with green stripe.

[Casey]

Make sure you play with the key a fair bit before giving up.  The lock mechanism often gets stiff.  The key needs turned to the left, such that it is at a 45-degree angle, so that the trunk will be unlocked, before pushing in the button.  If the key slot is straight up and down then the trunk is locked, if it is horizontal position then it should unlock/lock with the master door lock, but again vacuum leaks are common so be sure the car is running when you are trying.  If you can get the key to turn farther left past the horizontal position to 45-degree angle then it shouldn't matter what the state of the car or vacuum or door locks is - it should simply open.

[polymathman]

You've probably noticed that no quick and easy reply has been posted.

The trunk is VERY secure. You can't get access through the back seat, as it is completely separated from the trunk by steel - and if you could get through this, then there is the gas tank, and another screwed-in partition.

If the trunk release button pushes without resistance, you aren't making contact with the unlocking mechanism.

We will ALL be curious about how you solve this.

[mercedes350se]

Thanks for all the help everyone! I am going to try to work on it over the weekend to get it free. Just to clarify, when I lock the trunk I am able to push the lock in and it is free, but when I unlock the lock then try to push the lock in to open the trunk, the button gets stuck and the only way to release it is to relock the lock.

[Casey]

Any chance you can post a video on youtube?

[beagle2022]

Being of little brain I have to ask if you have tried squirting WD40 etc in and around the lock?  It isn't called wonder water for nothing.

[mercedes350se]

Any chance you can post a video on youtube?

Just took a small video and posted it on youtube. Maybe this video will show the problem a little better.

https://www.youtube.com/watch?v=O6XYEybbq2g

[Casey]

Oof, that doesn't look easy. Maybe a locksmith can be of assistance?

[mercedes350se]

Yeah its turned out to be a pain to deal with I think I'm gonna have to call a locksmith and see what they can do. Ill let you guys know what the problem is.