S class W140 reversing aid

[smeghead]

I have a 1995 W140 S500.

I have recently replaced the central locking pump. The car has the extendible reversing aids.

With the new pump when the ignition is on and reverse selected the aids extend to their full length. However when the car is started and reverse is engaged they only extend half-way.

Any suggestions

 

[eric242340]

The extending reversing aids are controled by the door assist pump located in the boot and not the central locking pump located under the rear seat. The door assist pump has a piple that runs to the main vacuum block located in the front passengers foot well and for this reason can be affected when the engine is running. I would start with leak problems from this pump line. Im used to LHD but your car is RHD, however the pump is normally in the boot on the left hand side over the wheel arch. You will have to remove all the felted covers to get to it.