The water pump is basically the heart of your cooling system in your Jeep. If your pump is starting to fail or leaking coolant, it won't be able to keep up with the cooling needs of the engine. If the bearing in your pump has seized up all together, it will make a horrible screeching and squealing noise with the engine running. If you've got any of these symptoms, it's time for a replacement water pump.
High performance water pumps, like those from Flow Kooler are capable of flowing a much higher volume of coolant during lower engine RPM. This can be especially beneficial while crawling down an off road trail and slow speeds where there will be less airflow over your radiator, but the engine will be under more stress.