Patent ID: 6131701
Filing Date: 2000-10-17
Classification: F01M,F02B,F16H,Y10T

Abstract:
For use with an automotive vehicle having an engine and an automatic transmission, the transmission having an internal pump operated when the engine drives the transmission so that ATF from the transmission is pumped through an external fluid circulation loop of the vehicle and back to the transmission, a method of exchanging used ATF from the transmission with new ATF comprising steps of:providing a source of new ATF;opening said external fluid circulation loop to provide a pair of loop connections, so that one loop connection of said pair of loop connections provides outflow of old ATF to waste;flowing new ATF from said source to the other loop connection of said pair of loop connections so as to effect a pseudo-closing of said opened external fluid circulation loop;providing a first conduit for conducting ATF from said one loop connection to one bi-directional flow port of a unitary hydraulic rectifier, and providing a second conduit for conducting ATF from another bi-directional flow port of said unitary hydraulic rectifier to said other loop connection;providing the unitary hydraulic rectifier with a unitary body defining four ports, and four intersecting passages each leading from a respective one of said four ports only to another one of said four passages, disposing a respective one of four one-way valves in each of said four passages, and disposing said four one-way valves so that one port of said four ports is exclusively an inflow port, one port of said four ports is exclusively an outflow port, and the other two ports of said four ports each allow bi-directional flow;providing fluid flow communication from said exclusive outflow port to waste, and from said source of fresh ATF to said exclusive inflow port.