You have to follow the procedure given below to replace the power steering pump on your 2005 Silverado. It is recommended to consult a mechanic if you are not familiar with Silverado and it's parts.
1) Disconnect the negative cable from the truck's battery. Remove the radiator's upper fan shroud by detaching any hoses connected to it and detaching its retaining clips and bolts.
2) Remove the serpentine drive belt. Make sure you know exactly how the belt was routed as it must be replaced in the same way. Place a drain pan under the power steering pump to catch any fluid that comes out.
3) Detach and remove the power steering pressure line and the return hose from the hard lines that are coming out of the pump. Disconnect the pulley from the power steering pump using a special power steering pump pulley remover to pull the pulley off the pump's shaft.
4) Remove the fasteners for the pump--this will be four bolts on trucks with V8 engines and two nuts in the back of the pump on V6 engines. Lift the pump off and away from the vehicle, making sure you don't spill fluid onto any truck paint.
5) Position the new power steering pump within the mounting bracket on the engine. Connect the mounting fasteners. Connect the pressure line and return hose to the pump. Tighten the fittings securely.
6) Press the pulley onto the pump's shaft with a power steering pump pulley installation tool. Re-install the drive belt and the shroud.
7) Fill the power steering reservoir with fresh fluid until it reaches the cold mark on the dipstick. Make sure the front wheels are facing forward, then start the engine and let it run at fast idle. Check the fluid level and add more fluid to the cold mark if needed.
8) Check the fluid level one last time after road-testing the truck to make sure the steering functions normally without any noise. You can get power steering pump here 2005 Chevrolet Silverado Steering Pump Parts from Buy Auto Parts
for your Silverado at good price.