Central locking delay on 107

[coleyjf]

Hi all

I've decided try to to fix a longstanding problem on my Euro(UK) 107 300SL. I think I know what the problem is but thought I'd ask for guidance as to the BEST place to start.

Problem:

LOCKING: when I operate the central locking from any of the three locks -doors and boot (trunk) the vacuum pump runs for ages after the car is locked but it does lock ok.

UNLOCKING:When unlocking with either the remote key fob ( factory fitted alarm) or one of the locks, mostly only one lock un-locks and although the pump runs a while it doesn't seem to work all three locks - the locks all work OK manually.

My thoughts:

I guess there's a leak in the vacuum system somewhere - possibly the drivers door hinge as I guess it gets most use?

MY QUESTION (sorry to be longwinded) do I start at the drivers door or has anyone a better suggestion ( I've already looked at the pump itself and checked the pipe connections)

Look forward to your help

Cheers

Jim