2-57. HEATER WATER CONTROLS.
HEATER KNOB. Allows operator to regulate flow of coolant through control valve.
CONTROL VALVE. Controls heater temperature by regulating flow of hot water to heater
core. Cable from heater knob in cab opens valve as knob is pulled out. Valve is spring-loaded
to close as knob is pushed in. Some water passes through this valve even when it is fully closed.
HEATER SHUTOFF VALVE. Supplies coolant to control valve. Manual shutoff handle
allows complete cutoff of coolant flow to heater.
HEATER RETURN TUBE. Carries coolant from heater to water pump.
HEATER SUPPLY TUBE. Carries coolant from control valve to heater.