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Vacuum Power Booster

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1997 Ford Pickup, 1997 Ford F-Super Duty, 1997 Ford Cab & Chassis, 1996 Ford Pickup, and 1996 Ford F-Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
  1. With a "T" fitting, connect vacuum gauge into vacuum line between engine and power brake booster. With engine at operating temperature, gauge should read 15-19 in. Hg vacuum at idle with transmission in Neutral. If reading is less than specification, stop engine, disconnect vacuum hose at power brake booster and cap open end of hose and open port of vacuum "T".
  2. Start engine, and allow it to idle. If reading is still less than 15-19 in. Hg vacuum, engine is producing low vacuum and mechanical problem must be corrected. If vacuum is to specification, check plastic check valve, rubber grommet and vacuum hose connection at power brake booster.
  3. With low engine vacuum corrected and/or leaking components replaced, start engine, and allow it to idle. Stop engine, and depress brake pedal for a few seconds. If vacuum drops to zero, booster is leaking and requires replacement.