Most low brake pedal problems are caused by air in the hydraulic system. Bleed the system until all air is purged. Refer to Antilock Brake System Automated Bleed Procedure in Antilock Brake System. Other less frequent causes of excessive pedal travel are excessively worn linings and hydraulic system leakage. At reasonably frequent intervals. Measure the brakes for pedal travel, which is the distance the pedal moves toward the floor from a fully released position.