I just replaced the PSE with a brand new motor. When powered on is it normal after turning pump on to just have suction only? I tested pump and both of the inlet/outlet tubes connected to the pump are just having suction.
Is this working correctly?

 

The pump must be capable of producing both positive and negative pressure.

This might help...
https://w220.ee/Pneumatic_System_Equipment_(PSE)_Pump

 

Thanks for the link, very informative.

I finally got this to work, when I replaced this with a new pump, I put back the vanes in the wrong direction.
I still need to fix at least one leak in the rear door, though.