Corrosion Preventing Characteristics of Military Hydraulic Fluids Part II

Hydraulic systems are widely used in a variety of military applications including ground vehicles, aircraft, and weapon systems. The impact of corrosion on hydraulic systems and its components is well understood; however, the protection provided by different hydraulic fluids is not equal. Review of military vehicle hydraulic systems has identified that the most common occurrences of critical corrosion are found in hoses, hose end fittings, actuator arms, pistons, cylinders, and rams. To prevent corrosion in hydraulic systems, the U.S. Army has specified the use of hydraulic fluids with corrosion preventing and rust inhibiting characteristics for ground vehicles. Currently, the Army uses three different types of fluids in the hydraulic systems of military ground vehicles and equipment; MIL-PRF-46170, MIL-PRF-6083, and MILPRF-2104. To verify the corrosion protection performance of the fluids, the Fuels and Lubricants Technology Team (FLTT) of U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC) continued an investigation to compare the corrosion preventing characteristics of military hydraulic fluids and engine oils based on standardized hydraulic fluid corrosion tests found in the hydraulic fluid specifications. The test results continue to show that MIL-PRF-6083 and MIL-PRF-46170 provide better corrosion protection than other non-rust inhibiting military hydraulic fluids. This follow-up report will provide updated test results demonstrating improved corrosion protection can be achieved for Army ground vehicle systems.