When your cars water pump is going out you may have an engine overheating problem, loss of engine coolant, squealing of the water pump bearings etc.
A cars water pump has a weep hole on the bottom of the water pump and when the water pump seal fails it leaks coolant out of the weep hole.
if you notice coolant coming out of the water pump weep hole then that is a sure sign the water pump has failed and needs replaced.
A water pump lasts between 30,000 to 100,000 miles before they go bad.
If your water pump does have 100,000 miles or more on it then it should be replaced as a preventative measure especially if you're planning a long road trip.
When a water pump does fail your cars engine will not cool down because the engine coolant will not go through the engine.