This SAE Aerospace Information Report (AIR) presents data on normally accepted changes in physical properties and contamination levels for military hydraulic fluids used in hydraulic test stands. This information is of importance to all users of hydraulic test stands to assure the performance data obtained on these test stands for specific components will not be adversely affected by excessive changes in fluid properties or contamination levels. The data pertains to fluids conforming to specifications MIL-H-5606, MIL-H-83282, MIL-H-6063, and MIL-H-46170. The guidelines incorporated in the AIR are the general consensus values of knowledgeable professionals. However, the experience and judgement of engineers and operators responsible for the equipment must be relied upon to determine when the hydraulic fluid is to be replaced. This document is essentially a metric document with English units.

Purpose:

The purpose of this report is to offer guidelines for deciding when the respective fluid has degraded to an extent that warrants replacement in hydraulic test stands. The most sensitive hydraulic components in systems using the subject fluids will dictate the limits of contamination or degradation permitted for each case. The guidelines incorporated in the AIR are the general concerns of knowledgeable professionals. However, the experience and judgment of engineers and operators responsible for the equipment must be relied upon to determine when hydraulic fluid is to be replaced.