C280 questions, door lock and vacuum pump - PeachParts Mercedes-Benz Forum

unkl300d · #1 08-13-2010, 01:13 AM

OK, This is such a great forum. Thanks to WHunter for his DIY sticky's and all forum participants.

My 1995 C280's driver side door lock is not working.
Without any prior symptoms or resistance etc., the door lock will turn with the key but it won't open or lock.
This operation must be done via the passenger door or trunk lock.

The DIY links show how to remove the inner door panel

http://www.202tech.com/howto/doorpanel.html

which I have not done yet, but I can't find info about the lock.

What could possibly have come loose or broken ? Is door panel removal needed for this repair?

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Vacuum pump location:

http://www.peachparts.com/shopforum/showthread.php?t=22228&highlight=w202+driver+door+lock

OK so I know where to find it.

My C280's vac pump groans periodically. I suspect it has a leak somewhere and the pump is cycling.

Everything seems to work fine so I can't be sure there is a leak.
Only odd issue is that the fuel gauge sometimes drops to empty even if the tank is full.
This is usually corrected after the car is shut off or by opening the gas cap after the engine is shut off.
The fuel breather pump at the front driver fender is working fine and has been replaced recently.

Has anybody had this behavior before.. the groaning vac pump at passenger rear area??

Door lock resolutions?

Thanks

mbdoc · #2 08-13-2010, 08:21 AM

Do both front locks FEEL the same when you put the key in & turn it?
Does the drivers door lock & un-lock when you use the passenger side key lock?

Does the LF one feel like there isn't any resistance?

unkl300d · #3 08-13-2010, 02:28 PM

MBDOC, hello and thanks for the questions.

The passenger side front door lock operates normally. Only the drivers side has no resistance, turns with the key but does not unlock or lock the doors
The passenger front lock has the same minor resistance that I have historically experienced and same normal resistance as with the trunk lock. This minor resistance is approximately the same as currently felt with my W126 300SE.
The C280's passenger front door lock and trunk lock will currently open and close all the door locks. With engine off I can hear the passenger rear fender-located door lock mechanism (vac pump?) make mechanical noise.
Just the driver side door lock has no effect with the turning of the key.
The key turns without resistance with that door.

Thanks

unkl300d · #4 08-15-2010, 02:42 PM

I found this.

http://www.peachparts.com/shopforum/showthread.php?t=149974&highlight=c280+door

probably the pin came loose.

UPDATE, evidently the 1995 C280's tumbler and spindle are a single piece. According to the dealer's schematic. Unless the OEM had a pin attaching the two and the replacement parts are now offered only as one piece ($85).
I found the single phillips screw at the end of the door just under the handle plane. The access hole in the frame is smaller than the screw head. I'm a bit reluctant to force it with a smaller head phillips driver.
Does the handle also have mounting screws behind the door panel????

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Not sure about the 'pump' noise yet. It is periodic like lasting 1-3 minutes. Maybe once or a couple of repeated times during a 25 min trip.
It also is emitting a high frequency noise from the front dash area, like a high note from rubbing a wet finger around a crystal wine glass lip.

some leads in archives... possible vac leak...???

unkl300d · #5 08-18-2010, 12:13 AM

Thanks to Ashman......

http://www.peachparts.com/shopforum/showthread.php?t=91028&highlight=w202+LOCK+REMOVAL

unkl300d · #6 08-18-2010, 01:35 AM

Thanks to the folks across the pond for a more precise description of how to remove the front door lock of a w202

Step 7 – Outside Lock and Door Handle Removal
• Pull out the rubber molding on the rear door edge in the vicinity of the outer door handle. This will expose an access hole thru the sheet metal on the inside surface of the door. Don’t confuse this with a second access hole on the back side edge of the door like I did.
• Using a 4mm allen screwdriver engage a screw behind the access hole. Completely disengage the screw. Don’t worry about dropping the screw; it is completely captive in the handle backing plate.
• Once the screw is disengaged, wiggle the lock mechanism up, back and out..
• By removing the lock portion of the handle you expose two screws on the outside face of the handle. Remove these and then remove the handle by pulling towards the rear of the door and outward. The inner backing plate is now also loose and can be removed by reaching up inside the door.

.....and from another thread with a picture

http://www.mbclub.co.uk/forums/bodywork/82280-w202-door-handle-removal.html

picture from UK club w202 1994

the trick is that there are two access holes at the door's end.
One visible prior to removing the weatherstripping just below the plane of the door handle and one visible after removing the weatherstripping aside and visible while peering into the vacant weatherstrip retaining 'furrow'. The latter is at horizontal level with the handle and the one giving access to the 4mm hex nut (allen wrench nut).
The former looks into a phillips screw head. NOT THIS.

The lock assembly is a piece aside from the handle.
follow instructions. no need to remove inner door panel.

Thanks mbclub UK !