PRECAUTIONS FOR MAINTENANCE 2.8.23 PRECAUTIONS FOR THE USE OF THE SYNTHETIC BIODEGRADA- BLE OIL TYPE HEES It is not possible to mix the synthetic biodegradable oil type HEES with ordinary hydraulic oils, since when the temperature increases insoluble compounds are generated, which are deposited on the filters and clog them (the maximum concentration of ordinary oil cannot exceed 1% of the total quantity of oil). The biodegradable oil can be used only in the hydraulic system; it cannot be used for the endothermic engine, the transmissions, the braking system, etc.
Before introducing the synthetic biodegradable oil in the hydraulic system, empty the system completely, dis- connecting the cylinders and all the parts that may contain ordinary oil, and replace the drain filter with a new one. Start the engine and let it idle without using the work equipment , wait until the oil reaches a temperature of at least 40°C, then start moving the equipment, so that all the parts of the system are filled with oil. Stop the en- gine and check the oil level (see “4.7.3.e CHECKING THE HYDRAULIC SYSTEM OIL LEVEL”). 53