I am being made into an evangelist for a product I have never used, and a company I don't represent.

But here goes anyway:

From: www.evanscooling.com/articles/aug98oc.htm

"Through the mid ‘70s, most antifreeze contained silicate additives which were abrasives that kept the mineral deposits, in the water, from building up in the cooling systems. Because the silicate additives were abrasive, they also destroyed water pump seals. A water-soluble oil was added to the antifreeze solution to protect the water pump seals. This oil was called water-pump lubricant.

If you used straight water in your cooling system during the summer months (distilled water worked best) you also had to add a pint of rust inhibitor/water pump pump lubricant to the water. Now you know why.

Of course, if there was a way to eliminate the water in the coolant, all of the problems associated with water would disappear as well."

As I understand it, the main purpose of using a water pump lubricant additive is to counteract and/or prevent the formation of rust & scale that will damage the water pump seals. The water pump shaft and bearings are "protected" within the seals themselves...

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."