Tthe truck uses and leaks coolant towards the front of the engine. About a cup every 2 months. I keep hearing about a "cold engine leak" with these models. 5.3L. Something about new style gaskets that will leak when the engine cools off. Checked around the water pump and the weep hole is clean.
coolant leak on 2000 Chevrolet Silverado 1500
Your leak may be coming from the seals between the water pump and the engine block. Pressurizing the cooling system when cold my help you find the cause of your leak.