Daewoo 220-5 excavator suddenly weakened and didn't brake. After listening to the analysis of our maintenance technician, Boss Chen affirmed its professionalism and asked to send a professional maintenance master to Tongren to repair the excavator. At the request of Boss Chen, the excavator maintenance factory sent Master Zheng, a professional technician from Daewoo, to Tongren to repair the excavator. Master Zheng took the K686 train on the afternoon of 5th. More than five hours later, the train arrived at Mr. Chen's construction site in Tongren. On the morning of the 6th, Master Zheng's Daewoo 220-5 excavator suddenly turned weak and had no brakes. "Fault maintenance: 1 On-site commissioning found that the excavator was weak in steering, but weak in both directions. Everything else is normal, no brakes. Push the arm by hand to start the engine, and it won't move after the flameout. Because there was no professional maintenance equipment on site, with the consent of boss Chen, it was dismantled and returned to Chongqing factory for maintenance overnight. On the morning of March 7, Master Zheng disassembled and inspected the rotary motor. After decomposition, it was found that the contact surface between the port plate and the cylinder was excessively worn, and the fault was solved after replacement. The above is the whole process of fault maintenance of "Daewoo 220-5 excavator suddenly weakened and did not brake" in Tongren, Sichuan. Further reading: Why is there no slewing brake after the port plate is worn? 1 First of all, the brake of this excavator is automatically released after starting, and it only starts to work after turning off the engine, so "you can push the arm by hand when starting the engine, but you can't push it after turning off the engine", which proves that the brake mechanism of this excavator is in good condition. After the oil distribution plate is worn, it is equivalent to internal leakage, which means that oil inlet and oil return are connected. But after starting, the brake was released, so there was no rotating brake.