Been a while since I was under the floormat of a 123 with a vacuum
pump, but if you pull up the driver side floormat, You should be able
to plug off the line going to the trunk until you get a new part.
The tool of choice is a golf tee.
On Tue, 22 Feb 2011 15:01:56 -0500 andrew strasfogel
<[email protected]> wrote:
The vacuum locking system on the 1985 300CD leaks down in about 4 hours
after locking the car.
Having trouble-shot the vacuum system on our '82 240D/3.0 over the
weekend, I have a fresh memory about the system -- I expect the coupe's
system to be similar to the sedan. Our leaks were so bad, the vacuum
system could barely shut off the engine.
Opening the master (driver's door) lock does not result in opening any
other door. (exception: when the vacuum is lost, the gas flap opens
automatically).
That's how things are supposed to work -- the FUEL filler flap is
single-action, locking only. When it looses locking vacuum, the spring
included on the vacuum element pushes it to the open position. That way,
you will always be able to fill the tank.
I have not pinpointed the source of the leak but suspect it's the oldest
vacuum element in the car - the trunk lock servo.
That's the one that was leaking on our car -- BOTH the lock and the
unlock sides! They cost $62.
This morning, I opened the master lock and went back to the (still
locked) trunk to open it manually by inserting the key in the lock,
turning it clockwise and pushing in the button simultaneously. The
trunk sprung open as expected, but what I did NOT expect was that it
REMAINED unlocked afterwards even though the vacuum power had already
dissipated. Can someone explain this?
Ummm ... counterclockwise?
The lock and the vacuum element both move a little flap into position or
out of position to transfer the inward motion of the button to the
unlocking mechanism. By opening the trunk with the key, you moved the
little flap into position and when you pushed on the button, it opened
the trunk. When you took out the key it was left in position because
using the key apparently moved the vacuum element's diaphragm, too.
To get to the trunk vacuum element, open the trunk and pry out the
plastic cover on the vertical portion of the inside of the trunk just to
the left of the lock. You will be able to see the locking (yellow/red)
and unlocking (yellow/green) Tecalan hard lines, two pieces of black
rubber tubing to connect the hard lines to the vacuum element, and the
vacuum element itself (ours is blue, like in
http://img.wpac.com/live/thumb/W01331624741VDO.JPG).
The vacuum element is held to the sheet metal by two self-threading
screws with 8 mm heads. Take the screws off and fish the element out
through the hole, twisting it in a vertical direction to disconnect its
arm from the arm that connects to the locks "little flap".
Once you have it out and the hard lines disconnected (DO NOT bend them
too sharply, they will break), you can check it out with your MityVac.
Right now, pending receipt of the element from Rusty, the two pieces of
rubber hose for our car are pushed onto the legs of a galvanized fencing
staple to maintain vacuum-tightness for both the locking and unlocking
sections of our vacuum system.
Craig
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_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
