First, check the hydraulic steering system for leaks. When the excavator has a large loss of hydraulic oil, the system pressure drops, the movement of the steering cylinder and the motor is not stable, and when the steering is slow and the power is not strong, the steering failure is considered as a leakage failure.
The main causes of leakage faults are as follows: wear and wear of seal parts or aging, oil pipe joints can not be matched, interface gaps, improper sealing or oil pipe rupture leading to oil leakage. Maintenance should be carried out in a timely manner.
Secondly, the quality and quantity of the hydraulic oil should be directly examined to directly affect the working state of the steering system. When the hydraulic oil is too small, the hydraulic pump will cause the steering of the machine to be slow due to insufficient oil supply. Therefore, the hydraulic oil should be added to the specified liquid level; when the hydraulic oil is not clean or there is foreign matter in the oil tank, the impurities enter the hydraulic system. After that, the seal may be damaged or the component may be damaged, so that the internal leakage is increased, thereby causing the steering to be sluggish. To this end, the oil quality of the hydraulic oil must be carefully checked. If impurities appear in the oil, the hydraulic oil should be replaced in time and the entire hydraulic system should be cleaned.
If the steering pump leaks seriously, it can also cause the machine to turn slowly. An important cause of leakage in the steering pump is that the gap between the rotor and the side of the blade and the end face of the side plate is too large (the normal clearance should be within 0.047 mm and the maximum should not exceed 0.100 mm). The inspection method is: when the steering cylinder, the central rotary joint and the steering gear are all in good condition, a new pump is replaced for comparison test; if the steering performance is good after the replacement, the fault is proved to be on the steering pump and should be replaced. New pump.
When the above component failure problems have been checked and removed, only the final step of the steering motor should be checked in detail. When the working surface of the stator and the rotor or the working surface of the rotary valve is severely worn, the amount of high-pressure oil actually entering the steering cylinder is reduced, resulting in a slow steering action. If the performance of the steering cylinder and the central swivel joint is intact, the steering wheel can be killed after the engine is turned off. If the front wheel of the machine can be deflected immediately and the hand feel is not heavy, it means that the steering gear has a problem. Repair or replace.