Decreasing Brake Pedal Travel
If a decreasing brake pedal is encountered, the power brake unit may be binding internally. To test the power brake unit for this condition proceed as follows:
1. Place transmission shift lever into Neutral and start engine.
2. Increase engine speed to approximately 1500 RPM, close throttle and completely depress brake pedal.
3. Slowly release brake pedal and stop engine.
4. Remove vacuum check valve and hose from power brake unit. Observe for backward movement of brake pedal.
5. If brake pedal moves backward, power brake unit has internal binding.
6. Replace power brake unit.