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 hydrophobic coating 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 hydrophobic coatings include, but are not limited to, polydialkylsiloxanes such as polydimethylsiloxanes. In one embodiment, a multilayer hose is immersed in a solution containing hydrophobizing siloxane monomers dissolved in a solvent. The coated multilayer hose is then dried to evaporate the solvent. As the solvent evaporates, the siloxane monomers bind together to form the hydrophobic coating. In some embodiments, one or more hoses each provided with a hydrophobic coating 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.