Abstract: A method of limiting pressure in a liquid cooling system of an internal combustion engine when the engine overspeeds, such as when an engine brake is applied.

Abstract: An auxiliary electrical power system for a motor vehicle is described. Generally speaking, the system includes a hydraulic pump, a hydraulic motor and an auxiliary alternator. The pump is coupled to and driven by the vehicle engine mounted within the engine compartment of the vehicle, and the pump operates to pump fluid at a pressure. The hydraulic motor is operatively coupled to the hydraulic pump and turns a gear coupled to the motor. The alternator has a gear coupled by a belt to the gear of the hydraulic motor. the auxiliary alternator is positioned outside the vehicle engine compartment to conserve space for other critical engine components. Further, the hydraulic pump may be coupled to the engine power-take-off shaft. The motor gear to alternator gear ratio is about 1:4 to allow charging even at low engine idle.