When diagnosing a coolant leak on your Ford Ranger the best possible scenario will be a busted radiator hose. The worst possible scenario is of course a blown head gasket. When troubleshooting your coolant system the best way to find out what is causing your coolant leak is by using a pressure tester. The pressure tester will locate the leak by pressurising the coolant system. If your water pump is the culprit the coolant will come out of the weep hole. This is an indication that you may have to replace your water pump.
Open the bonnet to reveal the engine compartment. The water pump is located in the front of the motor behind the fan.
Drain the coolant into a pan by opening the petcock valve located toward the bottom of the radiator. This will take a few minutes for all the water to drain.
Uninstall the belt by loosening the tensioner pulley. Use a 1/2-inch ratchet and turn the pulley till the belt loosens.
Take the fan off by loosening the four bolts holding it to the fan clutch. This will require a socket wrench.
Remove the pulley with a socket wrench to expose the water pump.
Unscrew the bolts holding the water pump in place. The water pump will ease out once all the bolts have been removed. You may need to pry as the gasket has created a seal. The water pump will work it's way out.
Be sure to organise all the components as you remove them. This will make the task easier when you are ready to put the new pump back in.
Do not attempt to work on coolant system when engine is hot. The coolant system is still under pressure and may result in serious burns.