How can a person check for a leak in hydraulic brakes?

1. Pump the brake pedal three times and hold the pedal for five seconds. If the pedal moves, there may be a problem.
2. Push the brake pedal down as far as possible and let go. If the brake pedal returns to its normal position, there may be a problem.
3. Push the brake pedal down as far as possible and let go. If the brake makes a squeak, there may be a problem.
4. Remove the rear wheel and listen for a noise when the brake pedal is depressed.