Vacuum brake booster (Renault 19)

All Renault 19 models have a brake booster, which provides about 60% of the braking force. This auxiliary device is located behind the main brake cylinder. The brake pedal acts directly on the pistons in the main brake cylinder, so that you can brake even with a faulty brake booster by pressing the brake pedal twice as hard!

The brake booster on a gasoline engine receives vacuum energy from the intake manifold, to which it is connected by a hose. Since the diesel engine has no vacuum in the intake manifold, it is equipped with a separate vacuum pump connected to the brake booster via a hose.

When braking, the pressure difference between the atmospheric air and the vacuum in the intake pipe or pump creates additional pressure on the pistons in the master cylinder. If the engine is not running, there is no additional braking force. Therefore, you must press the brake pedal harder if your car is being towed with the engine switched off, for example. If the engine suddenly stops on the road, you have the opportunity to make several short brakings thanks to the vacuum accumulator; then you will have to rely entirely on the strength of your legs.