Bypass check valves, suitable for bypassing a Venturi gap, are disclosed and include a housing defining an internal cavity having a first seat and a second seat, and a seal member within the internal cavity translatable between a closed position against the first seat and an open position against the second seat. The second seat defines a support structure having a middle region of a predetermine height and a downstream side having a height that is shorter than the predetermined height of the middle region. The seal member is seatable against the second seat with a downstream portion thereof a further distance from the first seat than an upstream portion thereof.

Methods and systems are provided for ventilating a crankcase in a boosted engine. An example method may include selectively enabling one of crankcase ventilation and aspirator motive flow via an electrically controlled valve, the aspirator motive flow being enabled in response to a demand for vacuum from a vacuum consumer. In this way, the crankcase of the boosted engine may be ventilated until the vacuum consumer demands vacuum.

Methods and systems are provided for ventilating a crankcase in a boosted engine. An example method may include selectively enabling one of crankcase ventilation and aspirator motive flow via an electrically controlled valve, the aspirator motive flow being enabled in response to a demand for vacuum from a vacuum consumer. In this way, the crankcase of the boosted engine may be ventilated until the vacuum consumer demands vacuum.

Method and apparatus are disclosed for adjustment of maximum brake pump speed based on rate of change of target deceleration. An example vehicle includes a brake pump having a maximum pump speed. The example vehicle also includes a vehicle decelerator to determine a target deceleration for autonomous deceleration and send a signal to the brake pump to decelerate the vehicle at the target deceleration. The example vehicle also includes a maximum speed regulator to determine a rate of change of the target deceleration and adjust the maximum pump speed based on the rate of change.

This blow-by gas recirculation device for an internal combustion engine is provided with a vacuum pump which supplies negative pressure to a brake booster and usable for recirculation of blow-by gas to an intake passage. This device includes: a PCV device for recirculating blow-by gas in a crankcase to the intake passage; a ventilation shortage region determination unit which determines whether or not an operational region of the engine is a PCV ventilation flow rate shortage region; and a brake negative pressure determination unit which determines whether or not the negative pressure of the brake booster is secured. The vacuum pump ventilates blow-by gas in the crankcase only when the determination units determines that the operational region is the PCV ventilation flow rate shortage region and that the negative pressure is secured. This reduces a contact risk of blow-by gas with engine oil, and inhibits the degradation of the oil.

This blow-by gas recirculation device for an internal combustion engine is provided with a vacuum pump which supplies negative pressure to a brake booster and usable for recirculation of blow-by gas to an intake passage. This device includes: a PCV device for recirculating blow-by gas in a crankcase to the intake passage; a ventilation shortage region determination unit which determines whether or not an operational region of the engine is a PCV ventilation flow rate shortage region; and a brake negative pressure determination unit which determines whether or not the negative pressure of the brake booster is secured. The vacuum pump ventilates blow-by gas in the crankcase only when the determination units determines that the operational region is the PCV ventilation flow rate shortage region and that the negative pressure is secured. This reduces a contact risk of blow-by gas with engine oil, and inhibits the degradation of the oil.

The invention provides a vehicle brake system including a brake assembly providing a service brake and a parking brake having a brake disc assembly in common, a service brake circuit, a parking brake circuit, and a brake control arrangement adapted to control the service brake by selectively providing a fluid communication between a pressurising arrangement and the service brake via the service brake circuit, the brake control arrangement further being adapted to control the parking brake by selectively providing a fluid communication between the pressurising arrangement and the parking brake via the parking brake circuit, and by selectively draining the parking brake circuit, wherein the vehicle brake system includes a draining circuit adapted to drain the service brake circuit to avoid overload of the brake disc assembly.

The invention provides a vehicle brake system including a brake assembly providing a service brake and a parking brake having a brake disc assembly in common, a service brake circuit, a parking brake circuit, and a brake control arrangement adapted to control the service brake by selectively providing a fluid communication between a pressurising arrangement and the service brake via the service brake circuit, the brake control arrangement further being adapted to control the parking brake by selectively providing a fluid communication between the pressurising arrangement and the parking brake via the parking brake circuit, and by selectively draining the parking brake circuit, wherein the vehicle brake system includes a draining circuit adapted to drain the service brake circuit to avoid overload of the brake disc assembly.

A vehicle braking system includes a brake pedal, master cylinder, a braking circuit with a wheel cylinder, and a brake pressure generator. A pedal feel simulator is coupled to the master cylinder output side through a switchable valve, the pedal feel simulator providing a reaction force. An isolation valve closes to isolate the braking circuit from the master cylinder and the simulator circuit. A primary pressure sensor generates a braking request signal responsive to the brake pedal. A controller activates the brake pressure generator to apply a braking force to the wheel cylinder based on the braking request signal. The controller identifies an abnormal value from the primary pressure sensor and couples the pedal feel simulator with a secondary pressure sensor within the braking circuit to determine whether the abnormal value indicates a primary pressure sensor malfunction or a malfunction of the pedal feel simulator or the switchable simulator valve.

An autolift-resistant piston assembly is provided for an air compressor. The piston assembly comprises an unloader piston having an interior chamber. The piston assembly further comprises a first coil spring for biasing the unloader piston to a loaded position when the piston assembly is installed in the air compressor. The piston assembly also comprises an inner member disposed in the interior chamber of the unloader piston and including (i) a body portion, and (ii) a tapered end portion extending from the body portion and facing an unloader air passage of the air compressor when the piston assembly is installed in the air compressor.