i was do basic maitenance checking fluids etc. i have radiator question . my overflow was on min line. i rode my scrambler 500 for about ten minutes around yard. when i parked it it was on the max line. later i opened radiator cap and it was full. where did this extra coolant come from?????? also how does the coolant get back from the overflow to the radiator??? there was a small drip on verflow fitting so i took some silicone and went around the fitting. sometimes this damn bike isnt worth all the trouble.

 

Same as in your car. When coolant heats up, it expands, pressure builds and it forces it's way into the overflow. As it cools and contracts, suction is created in the radiator that sucks it back in.

 

thats how i thought it worked, but the problem is it is not sucking back into the radiator . any suggestions.

 

I had a problem with mine not returning the coolant from the overflow bottle. I ended up replacing the overflow hose, as well as the radiator hoses and radiator cap at the same time. They were all fairly cheap. That took care of the problem. Also, do NOT get the hoses from the dealer. They will charge you and outragoues amount. All it is is 3/4" heater hose that you can get from the auto parts store for a couple of bucks. They dont have much of a curve in them so the regular heater hose works just fine. And the overflow line is just 1/4" (I believe) clear tubing. Very cheap at the auto parts store. The only hose that you need to buy from the dealer is the water pump hose. It is a special piece that is a u shape.