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Rad question

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JPSmit

JPSmit

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Was topping up the rad last night and got looking at the heater. Since the heater core is higher than the rad, will I be stuck with an air bubble or does the water pump flush it out?

And, if I do have a bubble, is that a problem?
 
I think it will flush itself out via the expansion tank but that's just a guess. At least that's what I assume since I don't have a problem with my bike.
 
Supposedly, the water flow into the heater comes in the bottom, forcing the air out the top and into the rad hose. This of course only would work if the flow is high enough to force the air down the return pipe. It does seem to work. The only problem a bubble would cause is reducing the heating effect of the heater. I suppose you could let the air out at the connection of the top heater hose by pulling it slightly off the heater while the system is under slight pressure.
 
I have had to drain and refill my radiator more times than I care to mention, and my heater still works great.

But it don't take much heater here in Texas.
 
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