I have a 2006 Monaco with a 8.8L 400HP Cummins side radiator . Recently I noticed the engine fan is running full speed all the time . I know the fan is driven hydraulically and I think it thermostatic...
Just returned from a 2000 mile trip. Side radiator was flushed before trip on return I could have filled a coffee can with the debris that I washed out of the radiator and cac. Bottom inch had about 1 inch of new debris stuck to it.
I wash mine at least 4 times a year.
Remember to use the Simple Green formula that is aluminum friendly. The regular is hard on aluminum.