FixVault

Check Valve

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
  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.