1. Install pressure gauge
Install a 50 bar pressure gauge at the make-up oil pressure measuring port to check the make-up oil pressure of the make-up oil pump. This port is located on the side of the pump body.
Install a 60 MPa pressure gauge at the system pressure measuring port to check the system’s operating pressure and maximum pressure. This port is located on the motor flush valve or on the side of the pump body.
Install a 2 × 10^5 Pa – 760 mmHg dual-purpose pressure gauge at the make-up oil pump inlet to check the make-up oil pump’s suction capacity.
Use an open-end wrench to check all pipes and fittings to ensure they are installed correctly and securely.
2. Filling the Oil Tank
Pour hydraulic oil into the oil tank. The oil level should be between 3/5 and 4/5 of the gauge. When filling, use a filler with a 10μm filter (the oil must be filtered to ensure it does not contain particles larger than 10μm or moisture).
3. Determine the Oil Level
If the oil tank is lower than the auxiliary pump, disconnect the auxiliary pump’s suction pipe and inject pre-filtered hydraulic oil. If it is a closed-loop pressurized oil tank, after loosening the suction pipe, inject 7×10^4 Pa of air pressure into the tank to force hydraulic oil through and fill the suction pipe and filter until no air bubbles appear in the oil. Simultaneously, ensure that all valves on the oil circuit are open.
If the oil tank is higher than the auxiliary pump, loosen the oil pipe connecting the auxiliary pump to the oil tank and check if the hydraulic oil can flow naturally through the oil pipe to reach the auxiliary pump.
If using a closed-loop pressurized oil tank, loosen the tank cap to allow venting to the atmosphere. If the oil cannot flow naturally through the oil pipe and filter, apply a low pressure of 7×10^4 Pa to the tank. If the oil still cannot flow through the oil pipe and filter, check for obstructions and ensure that all valves on the oil circuit are open.
4. Filling the Housing with Oil
Fill the pump or motor housing with oil through the top drain port. If it is a pressurized oil tank, open the top drain port on the motor. Oil will flow from the tank through the return line, radiator, pump body, motor housing oil line, and into the motor housing until the motor housing is full of air-free oil. This confirms that the pump, motor, and all lines are full. Ensure the valve on the return line is open.
5. Filling the Tank
Fill the oil tank completely to ensure the normal flow rate requirement of the replenishment pump.
6. Neutral Position Check
Check that the pump control handle is in the neutral position. Crucially, after releasing the mechanical linkage, check that the pump control valve is in the neutral position. If correct, reconnect the mechanical linkage.
7. Start the Engine
Start the engine and keep it idling. Do not accelerate the engine at this time. Run the engine for 30-40 seconds. The replenishing pressure gauge reading should be at least 13 × 10^5 Pa higher than the pump body pressure. Position the pump control valve in the neutral position and run it rapidly for about 5 minutes to ensure all parts of the system are filled with oil. If the replenishing pressure does not reach 13 × 10^5 Pa higher than the pump body pressure after 40 seconds, immediately turn off the engine and wait 5 minutes before trying again. If it still does not work, troubleshooting is required. If using an electric motor, do not exceed 15 seconds.
8. Measure the Pressure
Accelerate the engine to 50%–70% of full throttle. The measured replenishing pressure should match the hydraulic pump’s design replenishing pressure value. Note: Consult the hydraulic product manual to confirm the pressure values for each displacement replenishing pump.
9. Add Hydraulic Oil
Turn off the engine and check the oil level in the tank. If the oil level has dropped due to system replenishment, add hydraulic oil.
10. Start the engine
Start the engine again and accelerate to 50%–75% of full throttle. Slowly push the control lever forward; the rev counter pressure should be approximately 2.8 × 10⁵ Pa. Pull the lever to the neutral position and then slowly pull it back; the rev counter pressure should still be approximately 2.8 × 10⁵ Pa. Repeat this test 3–4 times.
Full throttle and check that the rev counter pump inlet pressure is not lower than 8 × 10⁴ Pa absolute pressure. Otherwise, its inlet line must be checked and reinstalled.