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. Check all power steering and 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.

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.

3. Ensure that the power steering pump reservoir is properly filled.

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

4. Check the power steering pump belt for wear and improper tension. Refer to Diagnosis of the Drive Belt System in Engine Cooling.
5. Check the power steering pump pressure. Refer to Power Steering System Test in Power Steering System.

1. Start the engine.
2. Apply the brake pedal, or turn the steering wheel from stop to stop. Either action charges the accumulator.
3. Turn the engine OFF.
4. Allow the vehicle to sit for one hour.
5. Do not start the engine. Apply and release the brake pedal several times.

Two or more applications should be power assisted.

6. Start the engine.
7. Charge the accumulator again.
8. Turn the engine OFF.
9. Do not start the engine. Apply and release the brake pedal several times.

Two or more applications should be power assisted.

•	If the accumulator will not hold a charge for one hour, but functions normally after charging, the accumulator valves are faulty. Replace the accumulator valves. Refer to Hydraulic Brake Booster Overhaul .

•	If the accumulator does not hold a charge, but can be heard charging and discharging, the accumulator valves are faulty. Replace the accumulator valves. Refer to Hydraulic Brake Booster Overhaul .

10. Apply the brake pedal several times. This will empty the accumulator.
11. If the accumulator's gas charge is exhausted, the accumulator can will rotate or wobble. Replace the accumulator assembly.