Series 55 – Section 3 Lubrication System Section 3 Lubrication System 3.1 Overview of Lubricating System 3.2 Oil Pump 3.3 Oil Pressure Relief Valve 3.4 Piston Cooling Oil Injection Nozzle 3.5 Oil Filter 3.6 Oil Cooler 3.7 Oil Level Dipstick Assembly 3.8 Oil Pan