When filled to the proper level after riding at 55mph for a while my coolant gushes out behind the glovebox. When the level drops it does not. Perhaps unrelated my temp gauge will go into the red zone soon after starting and drop back to normal temp if I hit a bump or hit the temp gauge with my hand, any suggestions or common experiences?
Perhaps loose / wet from coolant connection on the temp read / damaged temp sensor after your coolant loses.
Maybe the pipe attached to your coolant resevoir has a loose clip and when the coolants hot and the pressure is up it's squirting out until it's too low to continue.
It's pretty easy to remove the kick shield and ensure the pipe is on correctly. I had the pipe pop off completely but at the water pump immediately and as you'd expect the temp gauge went into the red.
You're going to have to take off the whole glovebox panel to investigate. If you're lucky it'll just be a loose hose clip that needs replacing - replace them all with Jubilee clips is best. It could also be a small split in the coolant reservoir itself - I've had to replace three on various bikes over the years.
While you're in there check the thermostat for proper operation (not too expensive to replace) and check the fan switch and fan work as intended.
Same as JimC said could be the hose clamps, the coolant reservoir itself and those are both best case scenarios. A worst case scenario is it could possibly be a warped cylinder head, bad head gasket or a combination of both. I had a very similar coolant leak as you described and that was my source of issue.
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