Hydraulic systems are precision units and their continue smooth operation depends on proper care. Keep them clean, change the oil filter at established intervals, and follow prescribed maintenance.

NOTE: FOLLOW LOCKOUT PROCEDURE BEFORE PERFORMING SERVICE TO EQUIPMENT.

1. Check the reservoir oil level and add oil as required. Refer to your equipment manual for oil specifications. The level must be maintained between the high and low marks on the sight gauge.
   
   
2. Check the operating temperature. 140 degrees Fahrenheit is considered maximum for most industrial applications.
   
   
3. If an external filter is used, check filter indicator for dirty element every two hours for first 8 hours of operation, and clear or replace when necessary. Check once every day for the next 5 days of operation, and clean or replace when necessary. Check periodically after that at intervals that will prevent the filter from bypassing or cavitating the pumps.
   
   
4. Check external filters as in Step 3. These are usually finer mesh filters; however, they will require more frequent element changes or cleansing than the internal filter. ALWAYS CHANGE FILTERS WHEN OIL IS CHANGED.
   
   
5. At least once a year or every 4,000 operating hours, the reservoir, pump, internal filter (if one is used), and air vent filter should be cleaned. At this time, check the entire system for possible future difficulties. Some applications or environmental conditions may dictate such maintenance be performed at more frequent intervals.
   
   
6. Make visual checks of all hose and tube connections. Regular checking and tightening of all hydraulic connections will help to assure trouble-free operation.
   
   
7. Periodically check pressure setting. The system was designed to operate at a specific pressure and increasing the pressure above that will result in motor overload. The system should be operated at the minimum pressure required to do the intended function, as the lower the system pressure, the longer system components can be expected to last.
   
   
8. Check pump/motor coupling periodically for misalignment. A flexible coupling should always be used and shafts accurately aligned parallel and angularly. Check set-screws in couplings for loosening, and tighten as required.
   
   
9. The reservoir cover should remain tightly sealed at all times, except in the case of in-tank maintenance and periodic checks for in-tank leaks. This is to prevent atmospheric contamination from entering the system.
   
   
10. On a dual pumping system, the pressure on each of the pumps must differ at least 20-30 psi. This will help keep the pumps from fighting each other for controlling your systems. Each month switch the higher psi pump to the lower setting, and the lower to the higher psi. This will help reduce wear on just one pump.

Posted 10 December 2001