Description & Operation
WARNING:
For warnings and procedures regarding vehicles equipped with Anti-Lock Brake Systems (ABS), see appropriate ANTI-LOCK article.
Hydraulic brake system uses a tandem master cylinder with a vacuum power assist servo. Sienna is equipped with front disc brakes standard, and rear drum or disc brakes. Rear drum brakes are self-adjusting.
Parking brake pedal mechanically activates rear brakes. With rear brakes, a cable applies rear shoes.
For 2004, the following equipment has been adopted:
- The ABS with EBD and Brake Assist are standard equipment on the FWD models.
- The ABS with EBD, Brake Assist, TRAC, and VSC, are standard equipment on the AWD models and optional equipment on the FWD models.
- A brake pressure conversion unit has been added between the brake booster and the master cylinder in order to provide the proper braking force when the brake booster has no vacuum.
- Dual mode drum brakes have been adopted for the rear brakes to improve parking brake performance.