All Renault 19 modifications have a brake booster that provides about 60% of the braking force. This accessory is located behind the brake master cylinder. The brake pedal acts directly on the pistons in the master brake cylinder, so 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 pipe, to which it is connected by a hose. Since the diesel does not have a vacuum in the intake manifold, it is equipped with a separate vacuum pump connected to the brake booster through a hose.
During braking, the pressure difference between the atmospheric air and the reduced pressure in the intake pipe or pump, respectively, creates additional pressure on the pistons in the brake master cylinder. If the engine is not running, then there is no additional braking force. Therefore, you must apply more pressure on the brake pedal if your vehicle is towed with the engine switched off, for example. If the engine suddenly stops on the road, thanks to the reduced pressure accumulator, you have the opportunity to make several short brakings; then you will have to rely entirely on the strength of your legs.