Constant Vacuum Hublock (CVH) Replacement
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Make sure to follow the Removal and Installation procedure exactly as instructed or damage to the hub can occur.
LH and RH side CVHs are not connected, other than by the common vacuum supply line. If a malfunction in either CVH is diagnosed, it should be installed as an individual unit; there is no need to "balance" an axle with new CVHs on both sides. It is highly unlikely that both CVHs are malfunctioning at the same time on a vehicle. If both sides appear to be malfunctioning, be sure to verify upstream integrity before installing new CVHs on both sides. Many system components are involved in the correct operation of the ESOF hubs. Before diagnosing the CVHs themselves as the cause of 4WD concerns, be sure to verify all related system components.