John, what temp did the guage show after the flush? I think about two gal. is normal volume in the system, I think I used a little over two gal. in
my 93 5.8,and I replaced my clogged up radiator with a larger one.
Did you burp the system after warmup,have you replaced the radiator cap?
If the water pump is not leaking it is probably still good.
My wife says I never listen,at least thats what I think she said.
1993 F150 XLT 4X4,5.8 5 speed
2000 Explorer Sport 4.0
2000 Ranger XLT 3.0