SAAB WIS ONLINE

Valve block

Valve block



A. To master cylinder

B. To wheel cylinder

C. Intake valve

D. Outlet valve

E. Pump element

F. Accumulator chamber

G. Pressure chamber


The valve block, that forms an integral unit within the hydraulic unit, modulates the brake pressure to the braking units during ABS controlled braking.

The electronic control module carries out a valve test every time the ignition is activated. The valve test is carried out together with a pump motor test. The valves are activated for 20 ms.

The valve block contains eight solenoid valves: four intake valves and four outlet valves. Each brake circuit has two intake valves and two outlet valves. There is one intake valve and one outlet valve per wheel.

In the brakes off position the intake valve is open and the outlet valve is closed.

In the valve block there is an accumulator chamber and a pressure chamber for each brake circuit. The accumulator chamber is located between the wheel brake unit and return pump and accumulates brake fluid before the return pump starts.

The pressure chamber is located between the return pump and the master cylinder and dampens noise and pressure surge when the return pump starts (ABS-mode).