i went out this morning to make a small idle adjustment. i went back out about a half hour later to leave for work. i noticed a small amount of coolant on the floor. i decide to drive to work and about 10 miles into the trip the gauge was on hot. i pulled over in a parking lot and had someone come pick me up. the overflow was full. i figured i would go back later and open the rad cap to see if its dry or not. how can you tell if your water pump is bad? i plan on topping off the rad if neccesary and trying to drive it home with someone following me. as long as i pull over if it goes up to the hot i should be ok right?