11 within which the seal elements are mounted and which contain isolated fuel inlet and fuel outlet or discharge passages which communicate with the vane slots in the fuel inlet arc and fuel discharge arc 26 areas of the cam chamber to admit fuel to the low pressure inlet buckets of the cam chamber and to permit the escape of the high pressure fuel from the discharge buckets of the cam chamber the single piece cam seal elements 28 and 29 of the present invention are less complex and more durable than prior known multi component cam seal elements used on variable displacement vane pumps of different types to serve the same purposes i e to seal the cam faces in the seal arc areas 25 and 27 of the cam chamber and to admit fuel or other liquid in the low pressure inlet arc 24 and to channel the fuel or other liquid from the high pressure discharge arc 26 to an outlet conduit while sealing the pump against axial leakage along the journal ends 12 and 13 of the rotor member 14 as shown most clearly by the sectioned view of fig3 and the face view of fig2 the cam seal elements 28 and 29 are identical to each other and are pressure loaded against the opposed cam faces to provide a 360 u00b0 outer peripheral seal except in the area of the fuel inlet grooves or passages 30 in the cam surface in the fuel inlet arc 24 of the pump shown in fig1 which communicate through fuel inlet passages not shown with a source of liquid such as a fuel at intermediate pressure and admit fuel into the arcuate opening to cam seal inlet passage 31 of the seal elements 28 and 29 to be.