If it is on the right side of the truck, back of the engine, after using the A/C it might be the condense water from A/C. It tends to drip on the chassis first and then on the floor, quite a lot though, but harmless.
could be freeze plug, or intake leaking
if you have a leaking water pump gasket i thing bay a new one is better
Your engine may have a leaking hose connection or a leaking gasket at the water outlet. It could also be a leaking hose.
Possible leaking hoses or water pump
Intake manifold gasket
ac or exhuast
Are you sure it is the water pump gaskets. It could be leaking some somewhere else, like the lower intake gasket
Heater core leaking?
If there is coolant coming from it and it isn't a hose.
When it starts leaking are making noise.
water leaking uper engin
If the pump is leaking or noisy then assume it is failing.