Bleeding a dual-brake system

The front and rear brakes of a dual-brake system have separate hydraulic circuits.

The configuration can vary depending on the manufacturer.

The brake pipes also pass through a balance unit which limits pressure to the rear brakes to prevent the back wheels locking when the weight of the car is thrown forwards during braking.

On some cars, the rear brakes cannot be bled if the weight is taken off the wheels, and the job must be carried out with the car on the ground.