Evaluation of Hydraulic Fluid Performance: Correlation of Water-Glycol Fluid Performance by ASTM D2882 Vane Pump and Various Bench Tests

The antiwear results of a series of hydraulic fluids were determined using various bench wear tests including: Shell 4-Ball, Pin-on-V-Block Falex Wear Test, SRV Ball-on-Disk, Timken Block-on-Ring and a recently developed cyclic contact stress (3-vane-on-ring) test and the ASTM D-2882 Sperry-Vickers V-104 vane pump test. These bench tests were selected since they are used in the fluid power industry for fluid selection, qualification and performance troubleshooting. The results of this work showed that none of the bench tests evaluated provided any correlation with the wear rates obtained with the ASTM D-2882 pump test. Comparison of these results relative to fundamental lubrication principles and published literature on similar problems showed that bench wear test correlations are possible only if the conditions of the wear test, such as wear contact geometry, loading, speeds, and materials reasonably model the specific wear contact of interest in the hydraulic pump. Even then, the general reliability of the bench testing conditions should first be demonstrated by hydraulic pump testing.