common problem
Troubleshooting of booster pump
Power steering pump is a high-performance power source in automotive power steering system. When the car turns, it provides assistance to reduce the driver's operating force on the steering wheel. It can also provide better steering stability for vehicles driving at high speed or on ice to ensure driving safety.
When there is a problem with the power steering pump, there are often the following failures:
01 heavy steering
02 abnormal noise of steering system
03 oil leakage
04 steering fluid produces emulsion foam.
05 vehicle deviation
Today, let's analyze the causes of these faults and how to eliminate them.
01 heavy steering
reason
The inside of the oil tank is too dirty, the filter screen is blocked or the oil level of the oil tank is low.
There is a lot of air in the power steering system.
Foreign matters in the steering system cause the flow control valve of the power steering pump to be stuck, and the parts in the pump are seriously worn, resulting in internal leakage of the pump.
The steering gear piston cylinder is excessively worn, the oil seal is poor, and the control valve is bonded or damaged.
Insufficient tire pressure, interference between pump and steering column, loose connection, loose pump belt, slipping or loose pump installation position.
The bolts at the connecting parts of the oil pipe are loose, resulting in steering fluid leakage and insufficient flow in the system.
Diagnosis and troubleshooting
Check the steering gear, power steering pump control valve, oil tank filter screen and steering oil, and clean the whole power steering system (clean it with kerosene as much as possible. The pump body cannot be disassembled. Disassemble the bolts on the pump control valve chamber, pour out the valve body in it and clean it simply).
If the pump is dirty, be sure to clean the inside and outside of the steering pump and oil pipe (not with cotton cloth or other multi fiber cloth, but with a clean brush). During the cleaning process, pay attention to the cleanliness of the system, and no visible impurities shall enter the pump and system.
Add oil to the specified oil level, check or replace the oil tank.
Adjust the tension of the belt as required and tighten the connecting screws of each component.
Check the connecting parts of the oil pipe and tighten the connecting bolts.
Replace the oil pipe, power steering or power steering gear.
02 abnormal noise of steering system
reason
The oil level of the oil tank is too low, the system has oil leakage or air, and the filter element in the oil tank is dirty, resulting in insufficient oil absorption of the power steering pump.
The internal cleanliness of the steering system is poor, resulting in excessive wear of stator, rotor, oil distributor, end cover and input shaft.
During the installation and connection of the oil pipe, there are problems such as blockage, bending, excessive deformation or resonance caused by poor system matching and poor oil inlet and outlet of the system.
The overload operation of the steering system causes excessive wear of the stator and rotor in the power steering pump, resulting in irregular movement of the oil in the pump, resulting in abnormal noise. If you turn the direction to the limit position in a short time of less than 6 seconds, the "hiss" will be normal.
Problems such as the low installation position of the pump or the poor driving road condition of the vehicle can easily cause a large amount of sediment and oil dirt to accumulate on the surface of the booster pump shell, which is easy to cause the input shaft of the booster pump and the ball bearing of the shell to be damaged by external impurities during use, resulting in corrosion by water, acid and alkali. If the whole steering system is not maintained on schedule, The ball bearing of the booster pump is easy to burn out or get stuck, and it is also easy to produce abnormal sound and heavy direction here.
The installation of steering gear and power steering pump on the support is loose, the internal wear of steering gear and improper adjustment of gear and rack.
The unreasonable matching of components between systems before delivery is easy to cause that the pipeline cannot absorb vibration, and the system will have abnormal noise, failure and other faults.
Diagnosis and troubleshooting
Clean the whole power steering system, remove the air in the system, adjust the belt tension or replace the belt, check and repair the oil pipe, oil tank, booster pump and steering gear, and replace the power steering oil and oil tank.
When replacing the steering high-pressure oil pipe, use the oil pipe with damping effect or well matched through the system.
Check other rotating parts, tighten the belt pulley, clean the power steering pump and steering gear, and replace the power steering pump or steering gear assembly under special circumstances.
If the pump is frequently in extreme steering for a long time, such as the coach car, it is easy to produce a large number of bubbles in the power steering system. If the abnormal sound in the system is reduced after replacing the oil, but the abnormal sound and a large number of bubbles appear after the road test, this fault has nothing to do with the performance and function of the pump and steering gear. The steering oil tank and oil can be replaced, It is better to have steps or curved tracks in the oil tank.
03 oil leakage
reason
At the oil inlet of the pump, if the oil inlet pipe is loose, oil leakage often occurs here. The press in force of the oil inlet pipe installation is 0.5-10kn and its anti loosening torque is 10nm. It will not be loose under normal installation and use. Therefore, it is required not to impact the oil inlet pipe on the pump at any time.
Check the oil pipe and the high-pressure oil outlet of the power steering pump. If there is oil leakage here, replace the sealing ring and tighten the mounting bolts on the oil pipe. This oil leakage fault is related to the quality of the pump, so it is not necessary to replace the power steering pump.
Oil leakage occurs in the oil tank. If the oil in the oil tank is filled too much, if the connection of the oil tank is not sealed tightly, or the engine vibrates greatly, it is easy to leak oil from the oil tank cover under the condition of bumpy road. This phenomenon is easy to occur and should not be considered as oil leakage from the pump or oil tank itself.
Diagnosis and troubleshooting
Carefully confirm and check the leakage position, replace all seals and oil pipes, tighten the bolts of all joints, and the installation torque of the large nut at the high-pressure oil outlet of the pump is 57-63n M. It is recommended that the torque of high-pressure oil pipe and its installation shall not be greater than 60N M. Otherwise, it is easy to damage the threads in the aluminum housing of the pump.
If the oil level is lower than the specified value, the power steering oil shall be supplemented in time. When filling the oil, it shall not exceed the mark on the indicator rod of the oil tank cover or the highest indicator label on the oil tank.
Clean the external leakage of booster pump, oil tank, oil pipe or relevant connections to accurately judge whether it is oil leakage or excessive oil filling.
04 steering fluid produces emulsion foam.
reason
There is air in the steering system.
There is fluid leakage in the steering system.
There are corresponding problems in the design of oil tank.
Diagnosis and troubleshooting
Exhaust the air, check for oil leakage and solve it.
Check and fill the oil tank.
05 vehicle deviation
reason
Loose steering wheel ball joint or improper front wheel alignment.
The steering linkage is distorted or excessively worn.
The rack preload in the steering gear is misaligned.
Poor steering wheel alignment, steering wheel shaking or beaters.
Diagnosis and troubleshooting
Adjust the front wheel alignment and the steering wheel ball joint.
Fill the steering fluid and exhaust.
Adjust or repair the steering gear rack preload.
Check and adjust all connecting parts in the steering system as required.