'91 7.3l radiator question

[Dave Sponaugle]

If you have a Cummins dealer close to you they have two good products. One takes care of solder bloom, the other takes care of scale in the iron block. Prestone green stuff is usually loaded with silicates, and says right on the label it protects aluminum blocks and radiators.

[harleyjohn45]

I just put new prestone in my truck, added napacool and installed a new lower hose. I do have radiator bloom, so out it goes. I also used 3 bottles of prestone radiator flush to really flush the radiator out. The flush removed some of the radiator bloom, but not all of it.