Prepare Gather several clean oil drums, two clean and rust-free iron drums, two gas cylinders filled with gas (for combustion purposes only), two burners for gas combustion purposes, a measuring spoon without fluff attached, as well as several cotton cloths without fluff for this project.
Separating Water by Heating and Cooling
Drain most contaminated and degraded hydraulic oil from its main pump suction pipe at one time, pour it into two metal buckets for heating, and set these buckets over flame for two or three minutes until temperature reaches between 78-82 in your oil drum (note this shortens heating time). As oil has lower density than water so they will naturally separate (oil on top, water below).
Once temperatures drop to between 68-72, use a ladle to gently scoop out and add 4/5 of any degraded oil back into the system, pour out and store away 1/5 of oil-water mixture, and finally dry your heating barrel using cotton cloth before returning it for future use.
Repeat Oil-Water Separation
Repete the oil-water separation action Begin excavator operations by performing compound movements to allow hydraulic oil temperature to increase to 50, repeating each movement at least 50 times over at least 30 minutes for at least two cycles, draining any remaining oil from system into heating barrel and repeat steps 2 and 3 until cycle has been repeated five times; when performing circulation process make sure to add fresh oil back in system during circulation process.
Discharge Oil in the System
After finishing its last cycle of movement, lay the excavator flat with all components fully extended such as boom, arm, and bucket retractions fully to allow as much hydraulic oil from its respective hydraulic cylinder and pipeline back to its tank as possible. Before turning off your machine drain all excess hydraulic oil from its tank, hydraulic cylinder, pipeline travel motor accessories etc.