SL/R129: Trunk Actuator Question
Thread Starter
Member
Joined: Feb 2003
Posts: 92
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From: Jupiter, FL
SL 550
Trunk Actuator Question
1997 SL 320 - my trunk actuator is only working to lock, not unlock the trunk.
In the unlock direction, I could hear air escaping, so I disconnected the yellow pneumatic line.
Apparently the pump provides vacuum to lock, and pressure to unlock, is that correct ???
I'm pretty sure the sliding part in the actuator is leaking...
Could someone verify this please ???
In the unlock direction, I could hear air escaping, so I disconnected the yellow pneumatic line.
Apparently the pump provides vacuum to lock, and pressure to unlock, is that correct ???
I'm pretty sure the sliding part in the actuator is leaking...
Could someone verify this please ???
Super Member
Joined: Aug 2005
Posts: 801
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From: Mercerville New Jersey
1991 560SEC Teal 1989 420SEL Ice Blue 1984 500SEC White
Have you tried this.
Unlock the trunk as well as the doors using the key if needed.
Now with all locks in the unlock position, try and relock the car, and unlock it.
The reason being is it appears as though you might have locked the trunk using the key. This engages one of 2 locks and it might be not disengaging the secondary lock.
Electronics go figure. The other would be to change out the fuses from the aluminum to copper. Corrects all kinds of eletrical gremlins.
Hope it makes sense
Bruce
Unlock the trunk as well as the doors using the key if needed.
Now with all locks in the unlock position, try and relock the car, and unlock it.
The reason being is it appears as though you might have locked the trunk using the key. This engages one of 2 locks and it might be not disengaging the secondary lock.
Electronics go figure. The other would be to change out the fuses from the aluminum to copper. Corrects all kinds of eletrical gremlins.
Hope it makes sense
Bruce
Thread Starter
Member
Joined: Feb 2003
Posts: 92
Likes: 0
From: Jupiter, FL
SL 550
Thanks Bruce !!! I tried that. Doesn't work.
The actuator will unlock, if I give it a little "help" with my finger, while the pump is running.
Also, the sound of air escaping tells me that the air isn't doing enough work...
I'd like someone to verify that the pump provides both vacuum (lock) and pressure (unlock) to the actuator.
Since the line only goes to one end of the actuator, this seems logical...
The actuator will unlock, if I give it a little "help" with my finger, while the pump is running.
Also, the sound of air escaping tells me that the air isn't doing enough work...
I'd like someone to verify that the pump provides both vacuum (lock) and pressure (unlock) to the actuator.
Since the line only goes to one end of the actuator, this seems logical...
Thread Starter
Member
Joined: Feb 2003
Posts: 92
Likes: 0
From: Jupiter, FL
SL 550
Well, I ordered a new actuator - $50 OEM ($200 + labor at dealer).
Mercedes has some really interesting disassembly features, but I finally figured it out. No tools required.
Being an engineer, I HAD to find out what the problem was, although the sound of air escaping was a real clue. The silicon diaphragm inside the actuator had a split in it, from wear, or possibly a bad batch...
The "vacuum pump" actually does supply vacuum one way, and pressure the other way. I hope they are more robust ($400).
Mercedes has some really interesting disassembly features, but I finally figured it out. No tools required.
Being an engineer, I HAD to find out what the problem was, although the sound of air escaping was a real clue. The silicon diaphragm inside the actuator had a split in it, from wear, or possibly a bad batch...
The "vacuum pump" actually does supply vacuum one way, and pressure the other way. I hope they are more robust ($400).
