A height control valve for controlling the relative height between a vehicle
frame
and a trailing arm suspension. The height control valve comprises a housing defining
an interior chamber and having an inlet port fluidly connecting to a source of
pressurized air. An air spring port is provided in the housing for fluidly connecting
to an air spring. Additionally, an exhaust port is provided in the housing for
fluidly connecting to the atmosphere. A valve is disposed within the interior chamber
and is selectively operable between a fill position, an exhaust position, and a
neutral position.