Abstract: A height control valve for an air spring of an air-ride axle/suspension system of a heavy-duty vehicle includes a body. The valve body is pneumatically connected to an air reservoir of the vehicles an ail spring, and to atmosphere A control arm actuates the valve to direct air from the reservoir into the air spring, when air is to be added to the air spring When air is to be exhausted from the air spring, the valve, actuated by the control arm, directs air from the air spring to atmosphere The valve includes a throttle assembly that can regulate the rate of pneumatic flow from the air spring to atmosphere when the vehicle is loaded and the air spring is in an extended condition. A throttle assembly can also be used to regulate the rate of pneumatic flow from the air reservoir to the air spring.

Abstract: A height control valve for an air spring of an air-ride axle/suspension system of a heavy-duty vehicle includes a body. The valve body is pneumatically connected to an air reservoir of the vehicles an ail spring, and to atmosphere A control arm actuates the valve to direct air from the reservoir into the air spring, when air is to be added to the air spring When air is to be exhausted from the air spring, the valve, actuated by the control arm, directs air from the air spring to atmosphere The valve includes a throttle assembly that can regulate the rate of pneumatic flow from the air spring to atmosphere when the vehicle is loaded and the air spring is in an extended condition. A throttle assembly can also be used to regulate the rate of pneumatic flow from the air reservoir to the air spring.

Abstract: A tire inflation system includes an air supply source in selective fluid communication with a tire via a pneumatic conduit. A method of inflating the system includes providing a tire pressure retention valve in the pneumatic conduit adjacent to the tire. An inflation pressure of the tire is determined with a step-up procedure, in which air bursts are communicated from the air supply source to a portion of the pneumatic conduit between the air supply source and the tire pressure retention valve. The volume of at least one selected communicated air burst is related to a volume of a section of the conduit. The tire is inflated with an extended-pulse procedure, in which extended bursts of air are communicated from the air supply source to the tire. A shut-down sequence is performed once a predetermined target inflation pressure in the tire is reached.