GM Service Manual Online
For 1990-2009 cars only

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.

The hydraulic power brake booster system works with fluid pressure from the power steering system. Therefore, a malfunctioning power steering system can affect the booster, just as a booster malfunction can affect the steering system. Before extensive testing, make the following checks:

    • Check all of the power steering and brake pipe connections for leaks or restrictions.
    • Check the fluid level of the brake master cylinder. Fill as necessary. Refer to Master Cylinder Reservoir Filling .
    • Check the reservoir of the power steering pump. Fill as necessary. If the power steering fluid contains air, refer to Power Steering System Bleeding in Power Steering.
    • Check the drive belt for wear and tension.
    • Check the power steering pump pressure. Refer to Power Steering System Test in Power Steering.