Escape 4WD V6-181 3.0L DOHC VIN 1 Duratec (2003)
Vacuum Brake Booster Check Valve: Testing and Inspection
Check Valve
1. Remove the vacuum booster hose from the power brake booster.
2. APPLY 57.3 kPa (17 in-Hg) of vacuum to the vacuum booster hose. If the vacuum does not leak off after ten minutes. the check valve is OK.
Otherwise, install a new check valve.