Analysis and Elimination of Common Problems of Tractor Hydraulic Steering System


As the application range of tractors becomes wider and wider, in order to meet the different needs of different users and adapt to the domestic and international markets, higher requirements are put forward for the hydraulic working system of the tractor, and the tractor is required to provide enough hydraulic output to meet the requirements of the supporting equipment. Use; the increase of supporting equipment has put forward new requirements for the steering control system of the tractor, requiring more flexible, light and reliable operation, so the hydraulic steering system has been more and more applied on the tractor, especially in the four-wheel drive It is more commonly used on wheeled tractors. Many people often encounter problems with hydraulic steering during use. Now the common faults and troubleshooting methods of tractor hydraulic steering are summarized as follows:


1. The steering is heavy or the steering wheel cannot turn

1. Cause of failure

(1) The fuel tank is out of fuel.

(2) The filter is blocked or there is air in the circuit.

(3) The internal leakage of the hydraulic pump is serious or the transmission lead slips.

(4) The safety valve leaks, the spring is too soft or improperly adjusted

(5) Damage to power cylinder or distribution valve sealing ring


2. Diagnosis and exclusion

(1) Check whether the transmission belt driving the hydraulic pump slips (or check whether the transmission gear driving the hydraulic pump is damaged).

(2) Check the steering gear, distribution valve, hydraulic pump, power cylinder and oil pipe joints for leakage.

(3) Check the oil in the fuel tank. If it is found that there is not only foam in the oil, there may be air in the oil circuit. At this time, the front axle can be erected or the straight rod can be removed to start the engine running rapidly. Repeatedly turning the swivel plate from one end to the other causes the power cylinder to expel air in a full stroke reciprocating motion.

(4) Check whether the hydraulic pump, safety valve and power cylinder are in good condition. Connect the pressure gauge and switch suitable for the specified oil pressure, turn on the switch, turn the steering wheel to the end, and start the engine to run at low speed. At this time, check whether the reading of the oil pressure gauge reaches the specified value. If the pump is good, the fault lies in the power cylinder and the distribution valve; otherwise, there is a problem with the hydraulic pump.


2. The hand feels heavy when turning the steering wheel quickly

1. Cause of failure

(1) There is more air in the oil.

(2) Poor use of the safety valve.

(3) The flow regulating valve does not work well.

(4) The oil supply flow of the hydraulic pump is too small.


2. Diagnosis and exclusion

(1) First, check the oil level in the oil storage tank and whether there is foam in the oil. If the oil is insufficient, it should be supplemented; if there is foam in the oil, it means that air has entered the oil circuit system, and the air leakage should be identified and eliminated, and then the air in the oil circuit should be discharged.

(2) Check the flow regulating valve and safety valve of the hydraulic pump. The two valves on the hydraulic pump can be removed, and after cleaning, they can be placed on a spring testing machine for inspection, or to compare the old spring with the new spring. If it is found that the spring elasticity is weakened, the free length is shortened, etc., it can be repaired or replaced as appropriate.

(3) When the above fault cannot be eliminated after replacing the spring or adjusting, it means that the fault is not on the two valves, maybe the hydraulic pump is worn, and the hydraulic pump should be replaced if necessary.

(3) When the above fault cannot be eliminated after replacing the spring or adjusting, it means that the fault is not on the two valves, it may be that the hydraulic pump is worn, and the hydraulic pump should be replaced if necessary.


3. Left and right steering feel different

1. Cause of failure

(1) The sliding valve of the distribution valve deviates from the middle position, or although it is in the middle position, it is inconsistent with the size of the seam on the shoulder of the valve body.

(2) There is dirt blocking in the slide valve, so that the blocking resistance is different when moving left and right.

(3) Improper adjustment of the adjustment nut of the distribution valve,

Fourth, the tractor deviates

1. Cause of failure

(1) The reaction spring of the distribution valve is damaged or too soft, so that the spool valve cannot be returned in time.

(2) The movement of the spool valve is blocked due to the dirty oil

(3) Due to the offset between the slide valve and the valve body step position, the slide is not in the middle position

(4) The flow control valve is stuck, so that the oil base of the hydraulic pump is too large or the oil pressure pipeline is arranged unreasonably, so that the throttling loss of the hydraulic system pipeline is too large, and the pressure difference between the left and right chambers of the power cylinder is too large.


2. Diagnosis and exclusion

First, check whether the oil is dirty. For new or overhauled locomotives, the oil change regulations after running-in are not carefully implemented, and the oil is often dirty. For locomotives that have been used for a long time, this fault may be caused by the failure of the flow control valve or the valve reaction spring. You can turn the steering wheel without starting the engine and judge whether the spool valve moves freely by hand. Generally, it should be disassembled for inspection.


This concludes the sharing of tractor hydraulic steering system problems and their troubleshooting. If you want to buy related hydraulic products, you can go to the official website of Hanjiu Technology Co., Ltd. Hanjiu has been engaged in the production of hydraulic products for more than ten years, and has accumulated rich experience in this field. The hydraulic products produced by Hanjiu have a complete range, good quality and low price, which can perfectly replace the products of big-name companies such as Danfoss. According to the feedback from customers of Hanjiu, the hydraulic products produced by Hanjiu have a long enough service life. In addition, Hanjiu adheres to the business philosophy of "customer first, service first", and always puts the needs and experience of customers in the first place. At Hanjiu, you can get the most meticulous and thoughtful service. Customized hydraulic products for customer needs, as long as you want, Hanjiu can help you do it! Hanjiu is looking forward to cooperating with you.


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