Pipeline of Hydrodynamic Transmission Transmission pump (inside the transmission gear) sucks the oil from the transmission gear (1) via the filter. The oil from transmission pump was transmitted to control valve of transmission gear via transmission oil filter (6). Then the oil was cooled by the radiator (4), and the cooled oil will cool and lubricate the transmission gear. 1. Transmission Gear 2. Hydraulic Oil Tank 3. Engine 4. Radiator 5. Carriage 6. Transmission Oil Filter 7. Parking Brake 20-22