The hydraulic booster uses fluid pressure from the power steering system. A malfunctioning power steering system can affect the hydraulic booster. A malfunctioning booster can affect the steering system. Before beginning extensive testing, perform the following procedure:

1. Inspect all of the power steering and the brake pipe connections for leaks and restrictions.

Notice: Power steering fluid and brake fluid cannot be mixed. If brake seals contact power steering fluid or steering seals contact brake fluid, seal damage will result.

2. Ensure that the master cylinder is properly filled. Refer to Master Cylinder Reservoir Filling .
3. Ensure that the power steering pump reservoir is properly filled. Refer to Checking and Adding Power Steering Fluid in Power Steering System.

If the power steering fluid contains air, refer to Power Steering System Bleeding in Power Steering System.

4. Inspect the power steering pump belt for wear and improper tension. Refer to the appropriate procedure from the following list:

•	Drive Belt Excessive Wear Diagnosis

•	Drive Belt Excessive Wear Diagnosis

5. Inspect the power steering pump pressure. Refer to Power Steering System Test in Power Steering System.

1. With the ignition OFF, apply and release the brake pedal several times. Applying and releasing the brake pedal will empty the accumulator.
2. Apply and hold the brake pedal with 180 N (40 lb) of force.
3. Start the engine.

The pedal should fall away and then push back against your foot.