What is the best way to flush the cooling system in a 1999 Chevy truck?

Answer 1

This takes some time to do, but it works good.

Remove the radatior drain plug, then put a garden hose in the top of the radatior.

Turn water on low until it is running over and start engine.

Now let it run until water coming out is clear, Then tighten drain cock up, fill Rad. up put cap on and go driven for a few miles. Then come back, And repete the same steps

until the water is running clear and clean. Then add antifreeze and your done.

You may have to do this several times to get it clean. Give it a try It's cheap