Hydraulic Pump Repair Kit40

Reasons and troubleshooting methods for slow walking
1. The sealing ring of the center rotary joint is damaged
The central rotary joint consists of two main parts: a shell and a core shaft. The core shaft is installed on the lower body of the vehicle, and the shell is installed on the upper body of the vehicle. The core shaft is equipped with an annular groove equal to the oil pipe. The hydraulic oil from the main valve core flows through the vertical hole on the core shaft of the shell to the motor, and the shell continuously rotates with the upper body. The groove on the core shaft can also be kept smooth with the oil port on the shell, and the hydraulic oil can freely enter and exit at the center joint. If the filter element of the hydraulic oil is not replaced in a timely manner, it may cause the bypass valve on the filter element to open, and the unfiltered hydraulic oil may cause impurities in the oil to directly enter the sliding surface of the center rotary joint, causing damage to the sealing ring on it. When the excavator is walking, the speed of the walking motors on both sides may be different due to pressure oil leakage on one side, resulting in the excavator walking deviation. The troubleshooting method is to replace the hydraulic oil and filter element simultaneously when replacing the oil on the center rotary joint
2. The balance valve in the parking brake oil circuit on one side of the excavator is filled with dirt
If dirt blocks the small hole of the balance valve when the excavator is walking, causing the parking brake to be unable to be released, resulting in walking deviation. This is because when the excavator is walking, if the pressure oil cannot enter the spring chamber of the balance valve through the small hole of the balance valve to push the balance valve core to move, the pressure oil cannot enter the hydraulic system through the groove on the balance valve, causing the parking brake force to not be released, As a result, the walking motor cannot rotate, resulting in walking deviation. Troubleshooting: Remove the balance valve and clean it. During disassembly and assembly, no dirt should enter; Regularly replace hydraulic oil and filter elements that meet the requirements.
3. The safety valve of the walking motor leaks oil
The oil leakage of the safety valve of the walking motor will cause the pressure in the system to be too low, resulting in insufficient rotation of the walking motor, leading to walking deviation. Troubleshooting method: Replace the damaged safety valve of the walking motor. When judging, the safety valves of the left and right travel motors can be swapped to see if they are deflected during reverse travel.
4. Dirt obstructs the small hole K of the balance valve in the final drive system, causing the parking brake to not be released
When the excavator is walking, if the pressure oil cannot push the balance valve core to move through the small hole K on the balance valve, the pressure oil cannot release the parking power through the groove on the balance valve, causing the walking motor to not rotate normally and causing the excavator to run off. Troubleshooting: Clean the oil circuit and pay attention to avoiding dirt from entering during future disassembly and assembly, as well as replacing the hydraulic oil and filter element on time.

SANY special oil Seal Repair kit 

├─For SANY Cylinder Seal Kit

SANY Excavator cylinder oil seals