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How does HRC expansion bottle work (NC35)? Cooling probs!

Posted: Wed May 10, 2017 6:03 pm
by Swift577
Hi all, I don't understand how the coolant bottle strapped to the rad with only an inlet pipe can replace the original/traditional set up for cooling. I have been very badly bitten by this too so want to get it right as I can't convert back to std due to subframe & fairings etc (unless anyone has another solution like a reservoir from another bike that fits nicely in tyga fairings!?).

My system gradually dumped all it's coolant into the bottle which managed to empty itself through the top I guess leaving it completely dry and getting engine massively overheat. Taken the thermostat out and it's obviously knackered I just don't know whether it was to start with. I'm pretty sure the fan and top rad never kicked in so I think now maybe not... I want to be able to run the bike for longish rides and a few times a week without having to top up coolant every time. What should I also replace/check to make sure I've set it up ok?

Thanks!

Re: How does HRC expansion bottle work (NC35)? Cooling probs

Posted: Thu May 11, 2017 5:44 am
by magg
Usually very little coolant should leave or enter the overflow bottle and any size and position should suffice. The bottle is simply to collect coolant that is forced past the radiator cap as the coolant heats up and expands. As it cools it is sucked back of the the bottle. Thus the hose into the bottle has to be immersed in coolant at all times. Most of the coolant should remain in the radiators and not in the overflow bottle, so if it does not then the is a cooling system problem, perhaps a dud radiator cap that fails to hold pressure.

Re: How does HRC expansion bottle work (NC35)? Cooling probs

Posted: Thu May 11, 2017 11:04 am
by CMSMJ1
it will find a balance - don't have the hose to the bottom of the bottle...

Re: How does HRC expansion bottle work (NC35)? Cooling probs

Posted: Thu May 11, 2017 5:38 pm
by Swift577
Great - thanks guys, think I am a bit happier about running it like this now! I'll make sure the pipe is immersed but not tight to bottom of bottle, then with new thermostat and rad cap hopefully all will be good! Cheers for the help, can't wait to get back out there!