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what should the excavator pay attention to when replacing the hydraulic oil?

Aug 03, 2018


1. Be familiar with the working principle, operating rules, maintenance and use requirements of the hydraulic system, so as to have a good idea and not blindly and arbitrarily.

2. Prepare new oil according to the oil specified in the manual, and deposit the new oil for more than 48h before use.

3. Prepare the tools for disassembling each pipe joint, the oil filter for adding new oil, the filter element of the hydraulic system, etc.

4. Prepare cleaning solution, brush and wipes.

5. Prepare the oil drum to hold the waste oil.

6. Select a smooth and solid site to ensure that the machine can turn without obstacles under the condition that the bucket and bucket arm are fully extended. After lifting the moving arm completely, it will not touch any obstacles. The distance from the wire should be more than bb0 b2m.

7. Prepare 4 sleepers so that they can block the track back and forth.

8. The operation personnel shall be at least 4 persons, including: one driver, one field commander and two oil changers.

B.Method and procedure of oil change

1, placing boom crawler direction parallel to, and stop after 45 ° position to the left, make the bucket cylinder was fully stretched out, and the bucket rod cylinder was completely retracted, slowly falling movable arm, make the bucket on the ground, and then the engine off, open the fuel tank vent valve, throw the operating handle, pedal several times back and forth, to release the pressure caused by the system such as weight.

2. Thoroughly clean all pipe joints, pump and motor joints, drain plug, top oil cap and bottom oil drain plug of the tank and surrounding areas with gasoline.

3. Open the oil valve and the oil drain plug at the bottom of the oil tank, so that all the old oil will flow into the oil drum containing the waste oil.

4. Open the fuel cap of the fuel tank, take out the oil filter element, and check whether metal powder or other impurities are contained in the residual oil products at the bottom of the tank and its edges and corners. Thoroughly clean the fuel tank, first clean it twice with diesel oil, then blow dry the tank with compressed air. Check if there is any residual sludge, impurities, etc. at the inner corner until it is cleaned and finally rinse with new oil.

5. Disassemble the following pipelines. If oil leakage is found, you can purchase imported hydraulic pipes from guangzhou zhongcheng electromechanical equipment co., LTD. For replacement:

Remove all the tubing in the lower return line, such as the main control valve to the full flow filter cleaner, the return oil filter cleaner, the filter to the oil tank, oil cooler between the tubing.

String disconnect rotary control valve to return tubing of filter and make-up tubing of rotary motor.

Remove the feed line of the hydraulic pump.

To open the return oil pipeline of the pilot system.

Rinsing the main pump and motor tubing. Thoroughly clean its tubing. The steel pipe is cleaned twice with diesel oil, and the hose is cleaned twice with cleaning liquid, then dried with compressed air and rinsed with new oil. Each joint is blocked with nylon, covered with a cover, or wrapped with a clean plastic cloth to prevent dust, moisture, etc. from entering and contaminating the system.

6. Remove the filter element of all filters in the system. When replacing the filter element, carefully check whether there is metal powder or other impurities on the filter element, so as to understand the wear and tear of parts in the system.

7. Remove the old oil in the main hydraulic pump, rotary motor and walking motor chamber and fill it with new oil.

8. Install the dismantled tubing. Before installing each oil pipe, it is necessary to clean the pipe joint again and wipe it with silk cloth. It is strictly prohibited to wipe the pipe joint with cotton yarn, towel and other fiber fabrics. Sealing tape should be used when installing threaded joints, and the direction of thread rotation should be opposite when pasting. Each pipe joint shall be installed and connected in sequence according to the specified torque.

9. Fill the tank from the oil inlet. Install the oil filter element first, then open the new oil barrel, fill the new oil into the oil tank with the oil filter, add the oil to the upper limit of the oil mark, cover the oil cap.

10. Replace the old oil in the following operating circuits. Before changing the oil in each circuit, the machine should be in three states: the bucket cylinder piston rod fully extended, the bucket cylinder piston rod completely retracted and the bucket freely placed on the ground.

Parallel lead control system circuit. Disassemble the control tubing joint of the left and right motor stop brake, make the selection valve in the middle position, drive the engine to idle several circles with the start motor, so that the pilot system can discharge the old oil in the oil road, then clean the pipe joint, and then connect it well. Start the engine and run at idle speed for 5min. Loosen the lead tubing connector on the control valve separately and operate each operation back and forth until new oil is discharged. Then, clean each pipe joint and connect it.

Parliamentary arms loop. Put the bucket on the ground, pull the handles back and forth several times, open the tubing joint of the moving arm cylinder without rod chamber, release the old oil in the hydraulic cylinder without rod chamber, operate the moving arm handle, and slowly pull the handle in the lifting direction. Loosen the tubing joint with rod cavity in the arm cylinder, operate the arm handle, and slowly pull the handle in the landing direction until the tubing eases out new oil. Operate the moving arm handle and slowly pull the handle in the lifting direction to discharge the old oil in the rod cavity, clean the pipe joint and connect it. Operate the arm up and down several times to expel air from the system.

Press the bucket loop. Loosen the tubing with rod cavity of the bucket cylinder, operate the handle, and slowly pull the handle in the direction of external rotation of the bucket. Clean the pipe joint and connect it until the new oil is discharged from the pipe joint. Open the pipe joint without rod cavity, lift the arm slowly, and make the bucket about 1.5m above the ground. Then slowly operate the handle of the bucket, turn the outside to the top, and drop the arm to make the bucket land. Operate the handle of the bucket, turn the handle slowly in the direction of the bucket, so as to drain the old oil from the tubing, clean the pipe joint and connect it. Lift the arm so that the bucket is 2.5m off the ground and turn the bucket inward and outward several times to expel the air remaining in the loop.

Croupier rod loop. Open the tubing joint with no rod cavity in the bucket pole cylinder, operate the handle, and slowly pull the handle in the direction of turning inside the bucket pole to discharge the old oil in the pipe until the new oil comes out. Clean the pipe joint and connect it. Loosen the rod cavity pipe joint of the bucket pole cylinder, release the old oil in the rod cavity, turn the handle slowly in the outside direction of the bucket pole, and push out the old oil in the pipe until the new oil is discharged, clean the pipe joint and connect it. Lift the arm, turn inward and outward to the bucket pole several times.

We're dealing with flow cytometry. Open the right (rear) end tubing connector on the rotary control valve, operate the rotary handle, turn it slowly to the right and then insert the rotary lock pin. Clean the pipe connector and connect it when no old oil is discharged. Use the same method to drain the old oil from the left rotary buffer valve.

Herring walking system. From the unilateral left tracks, to contact with the ground as part of bucket round face, and makes the movable arm and the Angle between the cattle stem for 90 ° ~ 110 °; Open the front tubing connector on the left running control valve, step down the left running pedal, and allow the left track to walk slowly forward until the pipe joint releases new oil. Clean the pipe joint and connect it. Discharge the old oil from the right running pipe in the same way.

11. When all the oil is replaced and all the pipe joints are connected, the residual air in the system shall be discharged again, because the residual air will cause poor lubrication, vibration, noise and performance degradation, etc. Therefore, the engine should run for at least 5 minutes after the oil change, and then operate the moving arm, bucket rod, bucket and rotary action slowly several times back and forth. If the walking system is in the state of single side-mounted crawler, the hydraulic oil can fill the whole system, and the residual air will be automatically discharged through the fuel tank after the movement. Finally close the vent valve.

12. Recheck the oil level of the fuel tank. The bucket cylinder piston rod is fully extended, the bucket rod cylinder piston rod is completely retracted, and the landing arm makes the bucket land. Check whether the oil level of the fuel tank is between the upper limit and the lower limit of the oil level meter. If the oil level is lower than the lower limit,), the oil should be added to the upper limit of the oil level.

C.Matters needing attention

1. During the oil change, it is strictly prohibited to start the engine when the fuel tank is not filled with oil, and the cavity of the hydraulic pump and motor is not filled with oil.

2. In the process of oil change, block must be placed before and after the crawler, and lock pin must be inserted in the rotary mechanism; It is strictly prohibited to stand under the bucket or within the action range of the bucket, bucket pole and arm.

3. When disassembling each pipe joint, make sure that the system is placed freely on the ground, and it can be disassembled only after confirming that the pipeline is free of pressure. When disassembling, people should try to avoid the direction of joint oil leakage. Wear protective glasses when you work.

4. When turning or walking the upper part of the excavator, the driver must press the horn to give a warning. It is strictly prohibited to stand on the upper side, as well as on the track and within the turning range.

5. When disassembling, do not damage the joint surface and thread of each pipe joint of the hydraulic system.

6. Smoking and open fire are strictly prohibited at the operation site.

7. When changing oil, it is better to finish it on the same day, not overnight, because at night or when cooling down, the moisture in the air will form water vapor, which will condense into water droplets or frost, and enter the system to rust metal parts, causing hidden trouble.