Trunk has quit closing - it will latch, but the auto pull down doesn't work.
Doors, locks and headrests work and the PSE pump is working....the trunk handle also pops out like it should....
Thoughts?

Pull down actuator leaky? Line to the actuator leaky?

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Trunk pull down failure is one of the first signs of pump failure. Reset switch #9 on the trunk and that should buy you some time.

Usually is the driver's doors self-closing mechanism and/or the trunk pull down to fail first as the self-closing vacuum pump starts to fail.

__________________
A. Rosich
CL 500, 1998
S 500 L, 1998
E 320 T, 1995 [Sadly sold ]

The pump is about 1 year old....assuming it is the same pump that operates door locks.
All close assist work - except the trunk.
Do the actuators get stuck or need lubrication?

Not the same pump on that car.
Closing assist on the W140 is a seperate pump in the trunk.

Does the pull-down work if you remove & re-install the fuse #9 in the trunk?

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

It works if I pull the fuse.
Is this an expensive thing?

Of course. the early VERSION lists for $1,200 & the 1994 & later lists for $750.

A lot easier to remove that fuse & re-install.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

But the removal of the fuse only buys you a little extra time. Pump failures between fuse removal will shorten in time up to a point where every time you close a door or the trunk you must reset the fuse to get the pump to work again.

When the pump failed on my S 500 L I replaced it with an aftermarket unit (cheaper than the original MB pump) but it only lasted for a year before starting failing again. So, I bought the original M.B. unit.

__________________
A. Rosich
CL 500, 1998
S 500 L, 1998
E 320 T, 1995 [Sadly sold ]

There is a good article on his site to tweek the pump, read carefully
http://v12uberalles.com/