What is the 2004 chevy silverado 2500hd coolant type?

The 2004 Chevy Silverado 2500HD uses dexcool that is orange in color. It is important that You do not mix different types of coolant because it can reduce cooling capacity and rust the lines in the engine. If You are not sure what coolant You have and it is low then the safest thing to do is add distilled water until You can get it to a shop. Usually if You have Your coolant changed at a dealership they will use dexcool, but a third party shop may use something different so it is always good to check with Your mechanic before adding more coolant. You should check Your coolant every time that You change Your oil to make sure that it is full.