An improved hydraulic system is provided for a reciprocating mold plate, patty-forming apparatus wherein food product is delivered under pressure from a pump cylinder to mold plate cavities. The plunger is driven during a first phase by force from a hydraulic cylinder from a retracted position distant from the pump cylinder to a ready position initially compressing food product loaded into said pump cylinder. Thereafter, the plunger is driven during a second phase by the hydraulic cylinder to load food product under pressure into the mold plate cavities. The hydraulic cylinder is supplied with hydraulic fluid during the first phase by a low pressure hydraulic fluid pump and during the second phase by a high pressure hydraulic fluid pump. According to the invention, the low pressure hydraulic fluid pump and the high pressure hydraulic fluid pump are positioned within a reservoir, at least partially submerged in hydraulic fluid held within the reservoir, during operation. The low pressure hydraulic fluid pump and the high pressure hydraulic fluid pump are connected in series to the drive shaft of an electric motor located outside the reservoir.