I have been using a waterless coolant in all my bikes and quad for about five years now. I use an Australian brand called Liquid Intelligence which is made here. It is like a thin oil to look at but is not an oil at all. Pretty clever stuff.
I had the usual water pump dribbles and after switching to the waterless have not had a leak since. I think the slightly slipperier consistency of the stuff helps the seal to seal and the sealing faces to glide over each other. It will never boil or freeze in this country, lasts forever, and the best thing for me is it doesn't corrode the alloy components (especially good for engines that sit for long periods) and I have never seen any stains around joints like you see with coolant.
It is a bit of a fiddle to clean out the old coolant and dry the insides (I like to leave mine open for a week or so to dry) but you only have to do it once, and in years to come will not be replacing components due to corrosion.
I recommend changing to waterless from new and never have a problem or change it again.
This is the one I use.
http://liquidintelligence.com.au/products/motorcycle-super-waterless-coolant