QuestionHi Mark,
I have a KFX400 that I had to drain, remove and remount the radiator in order to replace a damaged oil tank. When refilling the radiator my service manual instructs me to bleed air from the cooling circuit, but the manual offers no clear explanation on how to do this or why it needs to be done. I would appreciate any help.
AnswerHi Justin,
Review the tech file pasted below. It explains what you need to know about purging the iar from the cooling system.
Respectfully,
Mark Shively
Coolant Overheating & Servicing
By Mark Shively
Motorcycle and ATV cooling systems are air-free by design. Air in the cooling system lowers the boiling point of coolant to just above the point of which water boils and causes engine overheating.
Air enters the cooling system anytime the system is opened by changing the coolant, replacing the thermostat, temperature sensor, fan switch, or when other repairs requires draining coolant.
It is important to purge air from the system after servicing. The exceptions to this are opening the radiator cap or coolant reservoir cap for routine inspection and periodic maintenance.
The Mityvac Company manufactures a tool for purging air from cooling systems. The tool is the AirEvac tool. The Mityvac Cooling System AirEvac Kit refills cooling systems in minutes without trapping air that can cause overheating. The kit combines a universal adapter with a compressed-air-operated Venturi vacuum to quickly eliminate trapped air by purging and refilling the cooling system under vacuum.
The result is an air-free cooling system. Higher coolant boiling temperatures ensures a cool running engine and optimum performance.
