I've been dealing with rust issue developing in my coolant system. Ive flushed the block and radiator several times. Went to part store and used 2 things of prestone flush with distilled water. Then I went old school and went half vinegar half water which clear up most of it....but it still seems to build back after bout a month or so....I guess its time to do my water pump after noticing a water weep drip after parking today in the center of truck on the ground but I want to get a solution for the rust issue best as I can before putting on a new pump.....any suggestions? ????