K 3500 Truck 4WD V8-5.7L VIN R (1998)
Hydraulic Brake Booster: Testing and Inspection
Hydraulic Booster Noise Diagnosis
Normal Operating Noises
Hydraulic Brake Booster Diagnosis-Noisy Brake Booster
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.
5. Check the power steering pump pressure.
Noise from the relief valve is normal when applying the brakes. Firmly applying the brake pedal while the vehicle is parked also causes noise. The noises
