Bulldozer Komatsu D61-15 D65-15 D65-16 D85-15 Bulldozer Fan Motor Auxiliary Motor Cooling (Radiator) Fan Motor Part Numbers: 708-7S-00352, 708-7S-350, 708-7S-00550 The D65 (D65EX / D65PX / D65WX series) uses an electro-hydraulic static cooling fan system (HSS) . The fan motor is the hydraulic motor within this system—driven by pressure oil supplied from the engine-mounted fan pump (gear pump), replacing the conventional mechanical belt drive. Its speed is electronically