A long time of using the excavator will produce various problems, among which slow motion is one of the common faults. Here, slow motion is divided into many kinds. Today, according to the example of excavator repair, we will talk about the fault analysis and maintenance of Hitachi excavator's slow boom lifting and slow slewing.
A Hitachi zx300-5a excavator has been digging in the mountains for more than 6900 hours. The speed of lifting the boom of the excavator is very slow, and the operation rotation is also very slow. There are no other faults except boom and slow rotation.
The slow boom and slow rotation of the excavator may be caused by the fault light of the inlet and return oil circuit of the main safety valve, hydraulic pump, oil filter, hydraulic oil and distribution valve.
Hitachi zx300-5a excavator boom slow rotation slow fault maintenance:
1. Start the excavator operation boom at the construction site, and the speed is very slow; The operation rotation is also very slow. Check the oil capacity of the excavator oil tank, and the oil is sufficient; Check whether the hydraulic oil is clean and not dirty.
2. The excavator operated for about 30 minutes, and the hydraulic oil temperature was not too high. Disassemble and inspect the boom, check the boom spool valve and rotary spool valve, and there is no damage.
3. Check the boom cylinder and swing cylinder, and there is no internal leakage. Measure the system pressure: install a 40MPa pressure gauge on the hydraulic point, and observe the pressure value displayed when the boom is lifted at the specified speed of the engine? The pressure is 25MPa, lower than the specified pressure.
4. The reason for the slow rotation of Hitachi zx300-5a excavator is that the system pressure is too low. Adjust the pressure, then lift the boom and operate the rotation, and the speed is normal.
