1. Place the boom parallel to the direction of the track and stop after turning 45° to the left, so that the piston rod of the bucket cylinder is fully extended, the piston rod of the arm cylinder is fully retracted, and the boom is slowly dropped to make the shovel Put the bucket on the ground, then turn off the engine, open the tank bleed valve, pull the operating handles back and forth, and pedal the pedal several times to release the system residual pressure caused by its own weight.
2. Thoroughly clean the joints of the pipe joints, the pump and the motor, the oil drain plug, the fuel filler cap at the top of the fuel tank and the bottom drain plug at and around with the gasoline.
3. Open the oil drain valve and the oil drain plug at the bottom of the fuel tank to allow all the old oil to flow into the oil drum of the waste oil.
4. Open the fuel cap of the fuel tank, take out the fuel filter, and check whether the residual oil in the bottom of the tank and its edges and corners contains metal powder or other impurities. Thoroughly clean the fuel tank, first clean it with diesel oil, then blow dry the inside of the tank with compressed air. Check for residual sludge, impurities, etc. at the inner corners until they are cleaned, and then rinse again with fresh oil.
5. Disassemble each oil pipe.
6. Remove the filter elements of all the filters in the system. When replacing the filter element, carefully check the filter for metal powder or other impurities to understand the wear of the parts in the system.
7. Discharge the old oil from the main hydraulic pump, swing motor, and travel motor cavity, and fill it with new oil.
8. Install the oil pipe that has been dismantled. Before installing each oil pipe, be sure to re-clean the pipe joints and wipe them clean with a silk cloth. It is strictly forbidden to wipe the pipe joints with cotton fabrics such as cotton yarn and towels. Sealing tape should be used when installing threaded joints, and should be applied in the opposite direction to the direction of rotation of the threads. The pipe joints shall be installed and connected in order according to the specified torque.
9. Refuel the tank from the fuel filler. First install the fuel filter, then open the new oil drum, use the oil filter to fill the oil into the tank, add the oil to the upper limit of the oil mark, and cover the fuel cap.
10. Replace the old oil in each of the following action circuits. Before changing the oil in each circuit, the machine should be in the bucket cylinder, the piston rod is fully extended, the piston rod of the arm cylinder is fully retracted, and the bucket is freely placed on the ground.
11. When all the oil is replaced and the joints are connected, the residual air in the system must be discharged again, because the residual air will cause poor lubrication, vibration, noise and performance degradation. Therefore, after changing the oil, the engine should be operated for at least 5 minutes, and then the boom, the stick, the bucket and the swinging motion should be operated slowly several times. If the walking system is in the state of unilaterally supporting the crawler, the hydraulic oil can be used. Filling the entire system, the remaining air is automatically discharged through the fuel tank after being moved. Finally close the bleed valve.
12Recheck the fuel tank oil level. Fully extend the bucket cylinder piston rod, the arm cylinder piston rod is fully retracted, and lower the boom to make the bucket land; check whether the fuel tank oil level is between the upper and lower limits of the oil level gauge, if the oil level is lower than the lower limit, Oil should be added until the oil level is near the upper limit