Coolant flush

[brettfz6]

Hello, I just did a flush of my coolant system including draining the overflow tank. I've refilled with new coolant and ran to operating temp and checked to see if I needed to fill any more. The radiator was full still but the overflow had nothing in it. Is thay fine for normal operation or do I need coolant in that overflow tank under the seat? Any insight would be greatly appreciated.

 

[grahammarsden]

When the bike is cold, the reservoir/ expansion tank should be roughly half way between the Low and High marks.

As the engine heats, the coolant will expand and fill the reservoir and, if it get really hot, excess will run out of the overflow and drip onto the road.

When you stop and the bike cools, the coolant will be drawn back into the system and should stabilise between the Low and High marks again.

Best thing to do is to actually top it right up to the High mark, run it up to temperature with a rag under the overflow, then let it cool and see where it settles.

If you end up with nothing left in the reservoir, you need to take a closer look at the cooling system, radiator and water pump for leaks etc.

 

[brettfz6]

Thanks man I appreciate the advice! Im going to top it up tomorrow!

 

[Gary in NJ]

Also, make sure to “burp” the system to remove any air pockets. You will know if you have trapped air if you have a high temperature after just a few minutes of riding.