Hard Pedal

1. Internal vacuum leak.
2. Faulty control valve.
3. Broken or damaged hydraulic brake lines.
4. Collapsed or damaged vacuum hose.
5. Plugged or loose vacuum fitting.
6. Bad stud welds on front or rear housing on power head.
7. Faulty booster diaphragm.
8. Restricted air filter element.
9. Worn or distorted reaction plate or levers.
10. Cracked or broken power pistons or retainers.