Good Day all

I have great difficulty trying to gey these vacuum doorlocks on these (family) to work properly. .

I need to find out how one does a basic diagnosis of these systems to determine where faults typically might lie

On the old 280s vacuum comes from the manifold and the vacuum holding tank definitely gets vacuum but operation is sluggish with some doors staying unlocked etc.

On the 300E there is a vacuum pump under the back seat and this seems to run on for quite a while after the car is locked. Is the problem the pump or undetected leakages?

I can't detect any audible vacuum leakages on either car. Guidance from members with knowledge and own experiences will be greatly appreciated.

many thanks

ed (cumined) rep South Africa