Topics:
Brake force distributor:
The brake force distributor divides the braking force between the front and rear wheels. The front of a car must always brake harder than the rear. This is roughly a 60–40% ratio. The front wheels provide 60% and the rear wheels 40% of the total braking power.
Under braking, a car always noses down. Most of the weight then shifts onto the front wheels. As a result, the weight on the rear wheels decreases. If the rear wheels were to brake harder or just as hard as the front wheels, they would immediately lock up because there is hardly any weight on them. The result is that the wheels start to skid, greatly increasing the risk of an accident.
The brake force distributor is mounted in front of the rear axle of the car. When braking and the car noses down, the rear axle extends. The brake force distributor is then actuated and restricts the brake fluid pressure to the rear wheels. Less brake fluid pressure reaches the rear brakes, causing them to brake less hard.
If the car brakes even harder, the rear axle extends further. The brake force distributor now allows even less brake fluid to pass to the rear brakes.
When the car stops braking, it no longer noses down. The rear axle and the brake force distributor then return to the neutral position.
The brake force distributor is a mechanical component. Over time, due to various weather conditions, the pivoting action can deteriorate. The brake force distributor may seize, causing almost no brake pressure to reach the rear wheels. This is quickly noticed during the periodic inspection (APK) on the brake test bench. This leads to rejection. In this case, the brake force distributor must be temporarily disassembled, cleaned, and lubricated.
A photo of the brake force distributor will follow shortly.