A method (300) and control arrangement (210) for controlling a vehicle (100) to freewheel with engine off. The vehicle (100) has an engine (260) for propelling the vehicle (100) and a hydraulic power steering system (400). The hydraulic power steering system (400) comprises a primary power steering pump (270a) arranged to be driven by the engine (260) and a secondary power steering pump (270b). The method (300) includes: determining (301) when to start freewheeling the vehicle (100) with its engine off; and prior to starting the freewheeling of the vehicle (100) with engine off, determining (302) to start the secondary power steering pump (270b).

A method (300) and control arrangement (210) for controlling a vehicle (100) to freewheel with engine off. The vehicle (100) has an engine (260) for propelling the vehicle (100) and a hydraulic power steering system (400). The hydraulic power steering system (400) comprises a primary power steering pump (270a) arranged to be driven by the engine (260) and a secondary power steering pump (270b). The method (300) includes: determining (301) when to start freewheeling the vehicle (100) with its engine off; and prior to starting the freewheeling of the vehicle (100) with engine off, determining (302) to start the secondary power steering pump (270b).

A secondary steering pump system may include a secondary steering pump, a bypass valve having a first bypass position configured for placing the secondary steering pump in fluid communication with a hydraulic tank and a second use/testing position configured for placing the secondary steering pump in fluid communication with a steering control circuit. The system may also include a solenoid valve configured for actuation by a solenoid and for selectively actuating the bypass valve from the first position to the second position. The system may also include a pressure sensor configured for sensing pressure in the system.

A steering gear apparatus (2) for a motor vehicle (1), comprising a hydraulic steering gear (11) and an electromechanical actuator (7) which is configured to actuate a working valve (10) of the hydraulic steering gear, it being possible for hydraulic fluid to be conducted out of a fluid reservoir (14) selectively into one of at least two working spaces (12) of the hydraulic steering gear (11) in a manner which is dependent on a position of the working valve (10), the steering gear apparatus (1) having a fallback device (16) which is configured, in particular in emergency operation of the steering gear apparatus (2), to selectively conduct hydraulic fluid into one of the at least two working spaces (12) independently of the position of the working valve (10).

A steering gear apparatus (2) for a motor vehicle (1), comprising a hydraulic steering gear (11) and an electromechanical actuator (7) which is configured to actuate a working valve (10) of the hydraulic steering gear, it being possible for hydraulic fluid to be conducted out of a fluid reservoir (14) selectively into one of at least two working spaces (12) of the hydraulic steering gear (11) in a manner which is dependent on a position of the working valve (10), the steering gear apparatus (1) having a fallback device (16) which is configured, in particular in emergency operation of the steering gear apparatus (2), to selectively conduct hydraulic fluid into one of the at least two working spaces (12) independently of the position of the working valve (10).

A steering seal diagnostic system includes a steering linkage that is operatively connectable to a pair of road wheels. The steering seal diagnostic system also includes a sealed compartment containing at least a portion of the steering linkage. The steering seal diagnostic system further includes a pressure sensor positioned to detect an internal pressure within the sealed compartment over a range of travel of the steering linkage, wherein a pressure change lower than a pressure change threshold indicates a leak condition of the sealed compartment.

The hydraulic braking or steering system of a vehicle driven by a hydraulic motor is provided with a secondary supply of hydraulic pressure in the event of failure of the primary supply to the system. The secondary supply is generated by the hydraulic motor when ground-driven by the momentum of the moving vehicle.

An emergency steering system for a vehicle, may include a planetary gear mounted in an inlet space of a gear box for a steering apparatus so that the planetary gear is ordinarily operated at a gear ratio of 1:1 and has an increased gear ratio in the event of failure of a main steering device; and a gear ratio increasing device mounted to an upper plate portion of the gear box to increase the gear ratio of the planetary gear.

A system and method configured to direct the braking energy from a high-pressure port at the motor side of a hydraulic circuit to emergency steering, braking, accumulator(s) charging, and/or various work functions. The system and method are also configured to return hydraulic fluid back to the same high-pressure port when the motor is running as a pump.

A system and method configured to direct the braking energy from a high-pressure port at the motor side of a hydraulic circuit to emergency steering, braking, accumulator(s) charging, and/or various work functions. The system and method are also configured to return hydraulic fluid back to the same high-pressure port when the motor is running as a pump.