Vacuum Operated Engine Mounts Description and Operation Enclave

The system consists of the three individual mounts, a vacuum tank, an electro valve with a solenoid switch (part of the vacuum tank assembly), and the vacuum lines. When the solenoid is on, there is no vacuum in the mount system. When the solenoid switch is off, the valve is open and there is vacuum applied to the mount.

The mounts are activated, vacuum not present, when the electronic brake control module (EBCM) detects that the following condition is met: the engine speed is below 1100 RPM or the vehicle speed is below 32 kph (20 mph).

There are two distinct internal bellows within the mount that help make up the "switchable" mount feature: the idle and ride chambers. Fluid flows along different paths in the channel plate to each of these chambers.

At engine idle, fluid flow occurs in the smaller "idle" bellow chamber and the shorter path in the channel plate.

The EBCM monitors vehicle speed and engine RPM on the serial data circuit to turn ON the vacuum solenoid and supply vacuum to the mounts.

When the vacuum is applied, the idle bellow chamber comes in contact with the vacuum chamber. This causes a hydraulic lock of the fluid in the idle bellow and the path in the channel plate. The end result is the fluid is forced to flow in a longer path only switching the hydraulic effect in the mount.

At speeds over 32 kph (20 mph), fluid flow only occurs in the larger ride bellow chamber and longer path in the channel plate.