Forgot to tell you the cost of materials to flush the cooling system.
Degreaser $11.00
Citric acid(lemon acid) $17.00
Citric acid can be bought at your local Super Market. Look in the home canning section.
When I flushed my 300D, I didn't time myself but I would guess it took maybe three hours. Most of the time was spent just waiting for the chemicals to work. The hardest part was removing and replacing the drain plug. Have Fun.
Bill Lewallen Lexington,Ky.