Patent ID: 7357865

Claim:
An automatic transmission fluid filtration system for use within the hydraulic system of an automatic transmission of a land vehicle, said hydraulic system further including a hydraulic pump for generating a predetermined system pressure, said pump having a suction circuit and a pressure circuit, said hydraulic system including a wet sump wherein said automatic transmission fluid drains by gravity, said hydraulic system further including an original equipment fluid filter disposed within said wet sump in fluid communication with said suction circuit, said filtration system comprising: a replacement fluid filter disposed within said wet sump, wherein said replacement fluid filter includes a filter housing having an interior partition therein, said filter housing having an inlet in fluid communication with said pressure circuit and an outlet in fluid communication with said suction circuit; a coarse mesh filter element disposed within said filter housing, said coarse mesh filter element including a primary intake submerged within said wet sump in fluid communication with said suction circuit, said coarse mesh filter element further including a secondary intake; and a microfine depth filtering means disposed within said filter housing, said microfine depth filtering means having an inlet disposed in fluid communication with said pressure circuit for receiving said fluid at system pressure, said microfine depth filtering means including an outlet disposed in fluid communication with said secondary intake of said coarse mesh filter element, wherein said microfine depth filtering means carries out microfine particle filtration independently of said coarse mesh filter element such that volumetric efficiency of said pump is maintained in all phases of operation.