Engine System, Gasoline/LPG 105Service Manual – SW8000Replacing Engine CoolantOne possible cause of engine overheating is trapped air in the cooling system. It’s recommended that you usea Cooling System Tool when changing the engine coolant. The Cooling System Tool pulls a vacuum on thecooling system prior to filling to prevent air from being trapped in the cooling system.Note that there are several types of Cooling System Tools. The following instructions describe how to use atypical type of tool. Refer to the operating instructions included with your particular tool if different than theexample shown here.1. Connect a Compressed Air Supply Lineto the fitting on the Cooling SystemTool.2. Connect the Coolant Supply Line to theCooling System Tool. Make sure theCoolant Valve is closed.3. Insert and hold the Cooling SystemTool onto the radiator filler neck, thenpress the Air Switch. The compressedair travelling through the Venturi TubeAssembly will pull a vacuum on thecooling system to remove air from thesystem.4. Once the vacuum reading on theGauge reaches approximately 25 onthe green scale, release the Air Switch.Note that this also a good opportunityto check for cooling system leaks,5. Continue to hold the Cooling SystemTool onto the radiator filler neck andopen the Coolant Valve to allow coolantto flow into the radiator.6. Once the pressure on the Gaugereaches approximately 5 on the redscale and the radiator is almost full,shut off the Coolant Valve and removethe Cooling System Tool from theradiator filler neck.7. Top off the radiator and overflow tankas necessary.Compressed AirSupply LineAirSwitchGaugeCoolantValve(closed)CoolantSupplyLineVenturiTubeAssemblyRemoving the Air from the Cooling System with Cooling System ToolGaugeCoolantValve(open)Filling Cooling System with Coolant
