Not long ago, we received a telephone call from the owner of a CAT 320D excavator, whose excavator was experiencing various slow movements. "My machine is a 320D CAT Excavator, and I can't buy it for more than a year, and I have done a good job maintaining it, but somehow, it's working very slowly these days, even if it takes more than 10 seconds to spin around, and I can't do it at all."
We listened to a call for help and then asked some questions about the problem of slow CAT 320D excavator operation. We did a detailed failure analysis of the problem:
1 Boss, does your 320D engine speed work properly at full load?
Normal engine speed
2 Boss, when fully loaded, does your excavator engine smoke normal? Answer:
Normal engine smoke
3 Boss, what is your excavator usually used for? What is it used for in the near future? Answer:
My excavators are usually used on construction sites and have been helping people dig fish ponds recently.
4 Li Ban, do you have any idea of the 3 working modes of 320D? Are you using them? Answer: Not very familiar.
CAT 320D Excavator Slow Operation Fault Analysis:
After a general understanding of boss Wang's basic situation, we developed a solution for the situation from simple to complex:
The 1320D hydraulic excavator is designed with three different power modes: fine mode, common mode and heavy load mode. The engine power absorbed by the hydraulic system is 75%, 90% and 100% respectively. If the power mode is set in fine mode, the machine may move slowly. [Boss Liu checked and found that his excavator was set to heavy load mode at present]
2 It can be judged from the normal speed and smoke color of the engine, eliminating the possibility of engine problems, most likely from the hydraulic system.
Cause 1: Pilot system controls low oil pressure. [Pilot pump is one of the important functions of supplying pressure oil to pilot system, i.e. controlling main oil circuit to complete corresponding actions.
If the pilot system fails and the pressure in the pilot system is too low, the pilot oil will not be able to control the main control valve properly or the spool stroke of the main control valve will be too small, resulting in insufficient flow in the main oil circuit and possibly slow machine action]
Cause 2: Low pressure of main pump
Cause 3: The hydraulic oil circuit is not smooth and the hydraulic oil filter element is blocked.
