Running on water alone could be risky.

[Old Henry]

Just had a water pump fail after running the summer on water alone without antifreeze and only Hy-per Lube Super Coolant which, although it has rust, corrosion and electrolysis protection, no pump lubricant. Don't know for sure whether there is any cause and effect here but according to this service bulletin by NAPA there well could be. http://s7d9.scene7.com/is/content/Ge...29853pdf?$PDF$ I know there is one other surfactant type coolant additive that says not to run without some anti-freeze in the water. I'll probably keep at least some anti-freeze in for summer in the future.