You can make a model hydraulic brake system using the following :
Two disposable syringes
One rubber tube
One toy wheel
A pencil eraser
Two wooden blocks
First of all fix the wheel on to the wooden block with a nail in such a manner that it can rotate freely.
Fill the syringes with water and connect them both with the rubber tube. At the end of a piston of one of the syringes fix the rubber eraser. Using a tape fix this syringe to the second wooden blocks and then arrange every thing.
Rotate the wheel. Then press the piston of the other free syringe and you will see the piston of the fixed syringe coming out causing the eraser to stop the rotating wheel.