An inside surface of a hose for use with liquid-cooled cooling plate assemblies and other applications that contain copper (Cu) components is pre-treated with a passivating agent to reduce depletion of a copper corrosion inhibitor (e.g., benzotriazole (BTA)) dissolved in a liquid coolant (e.g., deionized water) that flows through the hose. Exemplary passivating agents include, but are not limited to, aliphatic alcohols (e.g., 1-hexanol), alkoxysilanes (e.g., (3-aminopropyl)triethoxysilane), and multidentate polymers (e.g., polyvinyl alcohol (PVA)). In one embodiment, a solution of pre-hydrolyzed (3-aminopropyl)triethoxysilane and deionized water is passed through a multilayer hose to form a pre-treated multilayer hose. In some embodiments, one or more pre-treated hoses interconnect liquid-coolant cooling system components (e.g., cold plates, headers, manifolds, pumps, reservoirs, and heat exchangers) of a cooling apparatus that removes heat from one or more electronic components.