The loader uses a flow amplification steering system, which is composed of a priority type flow amplification valve and a full hydraulic steering gear. There are two cases of heavy steering, one is that the steering wheel turns heavy, the other is that the steering wheel turns flexibly, and the whole machine turns heavy.
Heavy steering wheel rotation is generally caused by a failure of the pilot system. Check the pressure of the pilot system, pipe connections and pipe joints for problems.
The steering wheel rotates flexibly, and the steering of the whole machine is heavy, which is usually caused by a failure of the steering system. Check whether there is any problem with the pipeline connection, the oil suction pipeline, the pressure of the steering system, and the oil cylinder.
Before measuring and adjusting the system pressure, the whole machine should be parked on a flat ground, the boom should be lowered, the bucket should be leveled, and the engine should be extinguished to ensure safety. Before measuring the pilot pressure, first put the boom to the lowest position, and the bucket receives the position of the maximum retraction angle. Before measuring the steering pressure, first remove the ejector rod for the hydraulic limit.
The normal pressure of the pilot is: the engine is not lower than 2.2 MPa at the idle throttle and not higher than 5 MPa at the high-speed throttle.
When measuring the steering pressure, the car must be steered to the maximum angle, in a mechanical limit state, and the steering wheel must be kept in the steering state. When the engine is at high throttle, the steering system pressure reaches 15MPa.
If the above two measured pressures do not meet the specified values, they need to be re-adjusted. To adjust the pilot pressure is to adjust the overflow valve at the rear of the double pump. The steering pressure is adjusted at the end of the priority flow amplifying valve.
Check whether the pipeline connection is correct. This situation is mainly for old cars. At this time, it is important to check whether the pilot pump return oil and the limit valve return line are connected correctly. If the oil return line is connected incorrectly, it is easy to cause problems such as increased back pressure and heavy operating force. In addition, check whether there is air intake or oil leakage in the suction line.
Check whether the pipe joints are blocked. If the pipeline or joint is blocked by dirt, it is easy to cause problems such as increased back pressure and heavy operating force.
Check whether the oil cylinder has internal leakage, put the steering oil cylinder piston at the bottom, remove the rodless cavity oil pipe, and make the rod cavity continue to be filled with oil. If there is a lot of oil leakage from the oil port of the rodless cavity, it means that the piston seal ring is damaged and should be replaced. If the oil cylinder leaks, the pressure of the steering system will generally be low and the steering will be weak.