How To Pump Fluid Into Power-Pack Hydraulic Systems

The fluid in hydraulic systems serves the double purpose of transmitting pressure and lubricating the rubbing surfaces of the pump and other components.

The pump manufacturer’s recommendations for a high quality lubricating oil are strongly advised, based on the pump being the most highly-stressed component in the system.

All Formtek installations are designed for mineral oil. The hydraulic systems are mainly of the so‐called “power‐pack” type in which the hydraulic reservoir, hydraulic pump and driving motor, oil filter, breather & gauges are all combined into a single unit.

When oil is added, care must be taken to make certain the hydraulic system is clean and free of contaminants. Equipment used for dispensing the hydraulic oil must also be kept clean. In addition, all points of access to the system (such as fill caps or plugs, inspection plates, breathers, etc.) should never be left open to give dirt a chance to enter.

When the system is drained, as much of the old oil as possible should be removed. The tanks should be thoroughly cleaned to remove sediment. The filter elements should be replaced at the time the fluid is changed.  After the reservoir is cleaned, the system can then be flushed by circulating new fluid of the same type intended for use in the system.

The oil level should be inspected daily, or as frequently as deemed safe by the engineer in charge. If the oil level is permitted to get too low, the pump may draw in air, causing irregular operation of the pump and other circuit components, including excessive noise and accelerated wear of pump and valve parts.

Also to check frequently is oil temperature. Recommended operating temperatures are 80°F to 150°F. Temperatures above 150°F will shorten the service life of the oil and possibly cause malfunction of components.