1994 C8.3 Cummins Totorhome

[aort]

I have a 1994 FL70 totorhome with an 8.3 in it causing some problems. When I got it, the cooling system was dirty and was basically rust water. I flushed it out until I got clean water and changed the thermostats and it was fine. After some use the radiator developed a leak (probably from the flush). I did an inframe on the motor and found the liners had been pitted. So I replaced the radiator and tstats (180) too and it seemed to run hot. The fan comes on around 210-215 degrees. After looking at it, I think I got the wrong radiator. So I took it back and they gave me a bigger aluminum one. I put it in and it still seems to run warm. The upper radiator hose doesn't have any pressure on it before the tstat opens. The water pump does not have anything coming out of the weep hole. It does build a little pressure after the tstat opens. Should the fan just be coming on sooner? Could the water pump just not be flowing enough? Truck has 600k on it, so I'm not sure if it is the original pump or not.