How is it that the excavator boom descends very slowly and cannot support the truck?
Symptom: a 3800 hour Caterpillar cat324 excavator has a slow boom lowering and is difficult to support. What's the matter? Other actions of the excavator are normal.
The boom of Caterpillar cat324 excavator drops very slowly and cannot support the vehicle. The test data are as follows:
1. Boom lowering overflow pressure: 260 kg.
2. High pressure: 330 kg (other actions except boom lowering);
3. Pump control pressure: 33kg (other actions except boom lowering);
4. Pilot pressure: 40 kg.
5. Boom lowering secondary pilot pressure: 38 kg.
6. Boom lowering pump control pressure: 15kg.
Fault analysis:
Because -5 pump control is caused by the valve rod cutting off the neutral oil passage, it is estimated that the boom valve rod is not fully opened Boom lowering secondary pilot pressure: 38 kg The pilot pressure is enough but the boom valve stem cannot be fully opened? It may be that the valve rod is stuck in one direction by foreign matters (because the boom is lifted normally, it is stuck in one direction) Since the boom descends to a single valve rod, the main valve rod works. In addition, the main valve rod contains a one-way valve. Therefore, it is most likely that the plug of the one-way valve falls off, resulting in the failure of the valve rod to fully open The boom stem plug is loose, preventing the valve stem from fully opening.
Knowledge supplement:
What's wrong with the weakness of big and small arms of Caterpillar cat324 excavator?
Analysis: main relief valve failure Hydraulic cylinder failure The failure of the oil port safety valve will also cause the weakness of the large and small arms of the excavator The pressure, flow and data of the hydraulic system do not match, resulting in the weakness of the large and small arms of the excavator.
