F 550 2WD Super Duty V10-6.8L VIN V (2005)
Vacuum Brake Booster: Testing and Inspection
Brake Booster
1. With the transmission in NEUTRAL and the engine stopped, apply the brakes several times to exhaust the vacuum in the vacuum boost system or
the pressure in the Hydro-Boost system.
2. Hold the brake pedal in the applied position.
3. Start the engine.
4. If the power brake system is functioning correctly, the brake pedal can be felt to move downward after the engine starts.
5. With a vacuum type power brake booster, if engine vacuum is available to the power brake booster and no power assist is felt, replace the power
brake booster and retest the system.
If power steering pump pressure is available to the Hydro-Boost (R) power brake booster and no power assist is felt, replace the Hydro-Boost (R)
power brake booster and retest the system.
If power steering pump pressure is not available at the Hydro-Boost (R) power brake booster, check the power steering pump pressure and flow.
