Soft top operation, detailed description: Valves

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 pressure is reduced by two pressure reducing valves (for rotation anticlockwise and clockwise) to 140 ± 10 bar. These reducing valves are situated after the respective delivery sides and lead fluid back to the suction side. Meanwhile, the connection between the delivery side and the fluid reservoir is closed.

The valve block, containing three solenoid valves and two shunt valves, is connected to the pump block.

Each of the three solenoid valves has three fluid connections:

Fluid pressure from pump
Fluid pressure to main cylinder
Oil return to reservoir

The valves have two positions: "Active" and "Rest". When a valve is active, the pressure from the pump is connected to the pressure for the cylinder in question. When a valve is at rest, the pressure for the cylinder is connected to the fluid return line to the reservoir. The valves may be activated by STC.