Assistance is provided by reduced pressure in the intake manifold. The brake booster is connected to the intake manifold by a hose. When braking, the difference between atmospheric pressure and reduced intake manifold pressure displaces the large elastic diaphragm and puts extra pressure on the pistons in the brake master cylinder.
If the motor is not running, the servo control also cannot develop (additional) braking force. If the engine suddenly stops on the road, then you still have some reserve for a few braking. But after that, the calf muscles should work in full force.
Visitor comments