Deterioration and Maintenance

This chapter discusses the deterioration and maintenance of hydraulic fluids. Reliability surveys reveal the majority of service problems are due to contamination. Approximately 80%–90% of all faults in hydraulic systems, abnormal wear, valve malfunctioning, etc. may be ascribed to particulate contamination and inadequate filtration of the hydraulic fluid. One should keep a regular check of the particle count to ensure that the filters are working effectively. Oil level, service temperature and filters should be checked at regular intervals. Water absorbing filter elements should be used to remove relatively small volumes of water. The chapter also describes the various parameters that help in measuring the degree of oxidation, i.e., the level of chemical deterioration. It provides the maintenance. The last section discusses the process of flushing and how to use it. Flushing may often be required when the system is new or during subsequent service, particularly after repairs, if significant contamination has occurred. The various things one needs to do before flushing are outlined here.