Proper maintenance reduces your hydraulic troubles. By caring for the system using a regular maintenance program, you can eliminate common problems and anticipate special ones. These problems can be corrected before a breakdown occurs.

When a hydraulic system is worked on, cleanliness is No. 1. Dirt and metal particles can score valves, seize pumps, clog orifices, resulting in major repair work.

Oil and Filter Changes
Despite all the precautions you take when working on the hydraulic system, some contaminates will get into the system anyway. Good hydraulic oils will hold contaminates in suspension and the filters will collect them as oil passes through. A good hydraulic oil contains additives that work to keep contaminants from damaging or plugging the system. However, these additives lose their effectiveness after an extended period of time; therefore, oil changes at the recommended intervals can ensure that contamination is held to a minimum. By changing the oil at its recommended interval ensures that the additives will do their job.

Regular filter changes ensure solid particles are removed from the system. They should be changed more often under adverse operating conditions. When filters are changed, thoroughly clean the filter housing before installing a new filter. Remember to add enough fluid to compensate for any fluid lost in filter replacement.

Cleaning and Flushing the System
Cleaning and flushing the system should be performed based on the manufacturer's recommendation or when the system is known to be contaminated. The nature and amount of deposits in a particular system may vary widely. Inspection of the system may show any condition between a sticky, oily film and a hard, solid deposit (gum or lacquer formation) which completely chokes off the system. If the system is drained periodically according to the manufacturer's recom-mendations, the formation of gum and lacquer will be greatly reduced.

If there is no gum or lacquer formation suspected, clean the system as follows:

1. Drain the system completely.
2. After draining, clean any sediment from the reservoir, and replace the filter elements.

If flushing is required because the oil is badly contaminated, clean and flush the system as follows:

1. Drain the system completely.
2. Refill the system with the recommended hydraulic oil for the system involved.

3. Operate the equipment to cycle the flushing oil through the system. Ensure that all valves are operated so that the new oil goes through the lines.

NOTE

The time necessary to clean the system will vary, depending on the condition of the equipment. Usually from 4 to 48 hours is sufficient for most systems.

(Drain out the flushing oil, replace the filters, and refill the system with clean hydraulic oil of the recommended type.) If gums or lacquer has formed on working parts and the parts are sticking, remove the affected parts and clean them thoroughly. Consult the manufacturer's manual before removing and cleaning any parts for proper procedures.