Vehicle suspension with a dock height holding device

A vehicle suspension assembly includes a height holding device that is at least partially supported within an air spring of the suspension assembly. The height holding device includes a hydraulic ram. A moveable portion of the hydraulic ram moves between a first position where a minimum clearance is maintained between suspension components and a second position where a larger clearance is maintained between the suspension components. The height holding device moves into the second position to maintain a desired height of the truck or trailer bed during loading and unloading operations at a loading dock, for example. The height holding device allows for the suspension air springs to be evacuated of air pressure during loading or unloading conditions without a change in deck height.