Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
You first have to spin the fan off of the pump. You will need a big wrench to fit the clutch fan mounting nut " I think it is a 28mm". Then drain the cooling system, remove the belt and the upper and lower hoses, then unbolt the pump from the engine.
Make sure to clean all the old gasket material from the engine surface. bolt the new pump on with the gaskets provided with the new pump. Do not use rtv to hold gasket in place. Put the top bolts in the pump and then slide the gaskets over the bolts, then start the bolts no more then 2 full turns and then start the other water pump bolts, making sure the gasket is in place. tighten the water pump bolts down and put ever thing back on in revers order. fill cooling system with NEW coolant. Use dexcol only mixed 50/50 with water. let engine run till the thermostat has opened twice and refill coolant as needed.