Section 4 • Repair ProceduresREV BNovember 20084 - 30 GS-2668 RT • GS-3268 RT Part No. 1126576-3Flex PlateSee 4-4,Flex Plate.6-4Coolant Temperature and OilPressure SwitchesThe engine coolant temperature switch is anormally open switch. The switch contacts close atapproximately 221 °F / 105 °C. If the coolanttemperature rises above the switch point, theswitch contacts close and the engine will shut off toprevent damage. The engine will not start until thetemperature drops below the switch point.The engine oil pressure switch is a normally openswitch. The switch contacts close at approximately4.27 psi / 0.3 bar. If the oil pressure drops belowthe switch point, the contacts close and the enginewill shut off to prevent damage.A fault code will be shown in the diagnostic displaywindow at the ground controls when either switchcloses.How to Replace the CoolantTemperature and Oil PressureSwitches1 Open the engine side cover and pull up on thelock pin on the engine pivot tray located underthe radiator. Swing the engine pivot tray out andaway from the machine to access bothswitches.2 Coolant temperature switch: Tag anddisconnect the wiring from the switch, locatedat the engine coolant outlet just above thealternator. Remove the switch from the engine.Oil pressure switch: Tag and disconnect thewiring from the switch, located at the top of theengine just in front of the valve rocker cover.Remove the switch from the engine.Bodily injury hazard. Contact withhot engine fluids or componentsmay cause severe burns.3 Coolant temperature switch: Install the newswitch. Torque to 20 ft-lbs / 27 Nm.Oil pressure switch: Install the new switch.Torque to 88 in-lbs / 10 Nm.Note: Always use pipe thread sealant wheninstalling a new switch.PERKINS 403D-11 and 403C-11 ENGINES
