Abstract: A system and method for exchanging used hydraulic fluid with fresh hydraulic fluid in an accessed hydraulic fluid system. The system includes a fluid exchange assembly, a flow-aligning valve assembly and a locking mechanism. The locking mechanism allows the pressure of the fresh fluid being conducted to the hydraulic fluid system to be increased by a boost pump beyond the nominal pressure of the used fluid being conducted from the fluid system to the valve assembly during an exchange procedure. Together the boost pump and locking mechanism provide for an efficient exchange of fluids within a hydraulic system, particularly those hydraulic systems exhibiting relatively low flow.

Abstract: A fluid exchanger for servicing the fluid circuits of vehicular power steering systems and other fluid circulating or hydraulic circuits. The fluid exchanger uses a float operated fluid control valve to harness fluid pressure provided by a pump of an accessed hydraulic circuit. The fluid control valve uses both negative and positive pressure of the circuit's pump to control fluid flow patterns. The float and fluid control valve are matched to be either mechanical/hydraulic or electrical/hydraulic in design. If the exchanger is provided with a mechanically operated fluid control valve, a mechanical float is provided in the exchanger's fresh fluid reservoir and is directly connected to the valve slide of the fluid control valve. If the exchanger is provided with an electric solenoid operated fluid control valve, a float operated electrical switch is provided in the exchanger's fresh fluid reservoir and is wired to control the solenoid of the valve.

Abstract: A system for changing the fluid of vehicular automatic transmissions and power steering systems. The fluid exchange procedure of the present invention may include a bypass mode of operations whereby fluid from the vehicle is recirculated. The bypass mode of operations may take place before, during or after the exchange of used fluid with fresh fluid. The exchange system may also incorporate a flow alignment valve assembly whereby the operator may quickly and efficiently correct for a misconnection of the hoses into the accessed automatic transmission system or power steering system.