Noise caused by the relief valve is normal when the brakes are applied. Firmly pressing the brake pedal when the vehicle is parked also causes noise. Air temporarily gets into the fluid when the brakes are applied.

Power steering pump noise can be confused with transmission, rear axle and generator noise. Remove the power steering pump drive belt in order to determine if the noise is coming from a defective power steering pump. The noise will stop if the power steering pump is at fault.

Air in the fluid will cause noise. Fill and bleed the system after you disconnect a hose. Refer to Hydraulic Brake System Bleeding .

Use the following steps in order to locate and the correct the noise problems. Refer to Drive Belt Tensioner Diagnosis (a) in Engine Mechanical.

1. Inspect the fluid level. Adjust the fluid level as needed.
2. Inspect the hoses at the places where the hoses contact other vehicle parts.
3. Reposition the hoses as needed.
4. Inspect the fluid for air. The following conditions may exist if air is present:

•

Bubbles

•	Milky appearance

•	Extremely noisy operation

5. Bleed the brake booster system if air is present. Refer to Hydraulic Brake System Bleeding .
6. Inspect the power steering pump pressure. Refer to Power Steering Pump Specifications in Power Steering System.