Pump unit
WARNING: This page is about a different car, the 2011 Saab 9-3 and 2010 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
The pump unit comprises a 4-cylinder piston pump which is driven by an electric motor. The motor rotation direction is controlled by STC. The hydraulic cylinders work with differential pressure in certain cases, i.e. the same pressure operates in the system but due to the piston rod taking up part of the area the pressure has a smaller area to operate in at the piston rod side. The result of this is that the piston is pushed out faster but with less force.
The soft top hydraulic cylinders for the sixth bow and soft top cover are operated anticlockwise.