W202 Door lock failure

grenachenoir

Active Member
Joined
Jun 19, 2002
Messages
67
Location
North Yorkshire, UK
Car
W124 300CE
Yet another problem this week! The passenger side rear door lock has decided to stop working. It unlocks OK but instead of locking it gives a sigh (noticeable hiss of air) and fails to go down with other locks. Is this likely to be just a failed vacuum connection or is it more serious? How hard is it to pull the door apart to get to the locks? Any other ideas?

Adam
 

Malc

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Joined
Jun 1, 2002
Messages
88
Adam

It sounds like a faulty vacuum element. Easy to replace once you have the door trim off. Part should be quite cheap. I paid about £15 for the type with the electrical bits in it (front doors & boot lock), but I think the rear door will have a 'slave' version without any electrics, so it ought to be cheaper.

You can test the suspect element by removing it then sucking and blowing down the tube the vacuum pipe attaches to. If it operates in both directions, it's OK and the problem is elsewhere. That could be a leaky vacuum tube or a damaged junction - sorry, I've no idea how the pipes are routed and branched in a W202.

Good luck!
 
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grenachenoir

Active Member
Joined
Jun 19, 2002
Messages
67
Location
North Yorkshire, UK
Car
W124 300CE
Malc,

Thanks for your advice. I took the door apart today (why do they have to use so many annoying little clips??) and got to the vacuum actuator. There is a tiny (4mm) split in the rubber inside. I have tried gluing it for now and have a new assembly on order - £8.00 plus VAT from the dealer. The glue seems to be holding for now but I think i'll put in a new assembly anyway - just to be safe.

Looking forward to another hour pulling the door apart next weekend!

Adam
 

Koolvin

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W168, W169 & S202
Thanks for keeping us updated!

if you need spare clips the part number is : A 003 988 41 78
 
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grenachenoir

Active Member
Joined
Jun 19, 2002
Messages
67
Location
North Yorkshire, UK
Car
W124 300CE
Just to finish the thread. Took the door apart this morning - much easier 2nd time around - and replaced the vacuum acruator. All now working fine. Total cost £8.62 plus VAT. Something tells me the stealership would have charged a little bit more!

I even managed to save all the clips!

Adam
 

Malc

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Always good to hear about fixing a problem with a Merc for less than a tenner.
:bannana: :bannana: :bannana:
 

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