Abstract: A method/system for updating, between system calibration operations, the value (134') of a monitored control parameter corresponding to clutch incipient engagement is provided. At calibration, the initial values of the parameter corresponding to full engagement (124), incipient engagement (130) and the difference therebetween (132) are determined, and thereafter, the updated value of the parameter corresponding to clutch incipient engagement is determined as a function of a current value (124') of the parameter corresponding to clutch full engagement and the memorized value of the difference (132).

Abstract: An air circuit for a central tire inflation system having a relief valve (158) in the air circuit to provide the necessary pressure drop for deflation and having make up air from a source (S) bleed into the air circuit via one of two normally closed solenoid actuated valves (164, 174). The make up air is connected via a small orifice (214) when a solenoid (192) associated with a deflate valve (164) or a shut off valve (174) is energized.

Abstract: An improved wheel end valve assembly (11) for a central tire inflation system (10) having a single connection (68) to a tire chamber (74) and a single supply connection (62) to a source (142) of pressurized fluid, which requires no venting other than through the single supply connection (62), is effective in response to pressurization and venting of the single supply connection (62) to open and close communication to the tire chamber (74), a second valve means (288) to isolate the tire chamber if inflation pressure thereof falls below a minimum reference pressure, and a third valve means (300 or 400). The third valve means comprises a controlled bleed of air between the single supply connection and an isolation circuit (264, 254, 256, 266-276) by an elastomeric one way valve.

Abstract: An improved wheel end valve assembly (11A) for a central tire inflation system (10) having a single connection (68) to a tire chamber (74) and a single supply connection (62) to a source ( 142) of pressurized fluid, which requires no venting other than through the single supply connection (62), is effective in response to pressurization and venting of the single supply connection (62) to open and close communication to the tire chamber (74), and which is not affected by ambient temperature changes nor susceptible to leakage into and out of a trapped air volume employed by prior art valve (11) disclosed herein. The valve (11A) is actuated by air pressure and is resiliently biased into closed position by a spring (342) positioned within an evacuated bellows (334).