Mariner 4WD L4-2.3L VIN Z (2005)
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 10 minutes, the check valve is OK.
Otherwise, install a new check valve.