The overall efficiency of the hydraulic installations used to control or drive auxiliary machines is basically dependent upon the size, oil pressure, speed, and stroke of the hydraulic installation. The efficiency of the hydraulic speed gears and the components of the system as a whole will depend upon the care which is given them. Since major repair of hydraulic gear, except for piping and fittings, is generally done in a naval shipyard or by the manufacturers, this section will deal primarily with troubleshooting and preventive maintenance.

Hydraulic transmissions are sturdy, service-proven machines, inspected and tested with such care that casualties seldom occur except as a result of faulty assembly, installation, or maintenance. A correctly installed hydraulic system, operated regularly and serviced with proper care, will re-tain its design characteristics of power, speed, and control. The need for costly repair and replace-ment will seldom occur if the equipment has been maintained properly.

TROUBLESHOOTING

Troubleshooting an electrohydraulic system involves the systematic elimination of the possi-ble causes, one by one, until the actual cause of a casualty is found. In attempting to locate the source of any trouble in an electrohydraulic system, remember that all troubles occur in one of three categorieshydraulic, electric, or mechanical. Isolating a trouble into one of these categories is one of the main steps in locating the source of trouble.