Ranger 2WD V6-245 4.0L VIN X SFI (1997)
Vacuum Brake Booster Check Valve: Testing and Inspection
Vacuum Hose, 4.0L MFI: Engine
INSPECTION
Inspect the power brake booster vacuum hose for cracks, damage or collapse. Replace as necessary. Verify proper routing of the vacuum hose.
Reroute as necessary. Remove the vacuum hose from the vacuum inlet port on the power brake booster and inspect the power brake booster check
valve for damage and improper mounting. Apply vacuum and pressure to the power brake booster check valve and verify that air would flow only
toward the engine. Check that all hose clamps are tightened securely.
TESTING
To test the functioning of the power brake booster check valve:
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Start and run the engine for at least 10 seconds.
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Operate the brake pedal to check for power assist.
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Disconnect the vacuum booster hose from the power brake booster.
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There should be enough vacuum retained in the power brake booster for at least one more power-assisted brake operation.
