You're generally not going to be able to tell whether your water pump is working by feeling anything - it's designed to move volumes of coolant, not create pressure. A water pump is dead simple though, and if it's turning, it's pretty certain that it's pumping. Unless it's leaking, there's no reason to replace it by itself. If you're replacing the timing belt though, then it just makes sense to replace it at the same time.

95 Montero SR
3.8 MIVEC, Advance headers, 2 1/2" exhaust, Magnaflow muffler, OME shocks & rear springs, 2" body lift, 3" tank lift, 4.90s, TRE front locker, factory rear locker, Roger Brown Rock Sliderz, 315/75r16 (35") tires, Sport big brakes