E 150 V8-4.6L SOHC VIN W (2004)
Vacuum Brake Booster: Testing and Inspection
WARNING: Use of other than the approved DOT 3 brake fluid will cause permanent damage to the brake components and will render the
brakes inoperative.
NOTE: If a vehicle with a locked wheel must be moved, loosen the bleeder screw to relieve pressure.
Always check brake fluid level and, if necessary, fill with clean DOT 3 brake fluid.
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.
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, install a new power
brake booster and retest the system.
If power steering pump pressure is available to the Hydro-Boost power brake booster and no power assist is felt, install a new Hydro-Boost power
brake booster and retest the system.
If power steering pump pressure is not available at the Hydro-Boost power brake booster, check the power steering pump pressure and flow.
