How to tell if the power steering pump is broken or the rack gear is broken?
The power steering system is an indispensable part of modern cars. It allows the vehicle to steer easily at low speeds, greatly improving driving comfort and safety. The core components of this system include the power steering pump and rack gear. The power steering pump is responsible for pressurizing the hydraulic oil and transmitting it to the rack gear system to assist steering.
However, when there is a problem with the steering system, it is often difficult for car owners to determine whether the power steering pump is faulty or the rack gear is faulty. This article will analyze the different fault manifestations of the two in detail to help car owners effectively determine the root cause of the problem.
How does the power steering system work?
Before understanding how to judge the problem, you first need to understand the working principle of the power steering system. The hydraulic power steering system mainly consists of three parts: power steering pump, hydraulic oil and rack gear.
● Power steering pump: The power steering pump is driven by the engine, and the rotor in the pump is driven by the belt to rotate, sucking the hydraulic oil from the tank, and then pressurizing it to the steering rack. The function of the pump is to provide the required hydraulic pressure for the system.
● Rack and pinion: The function of the rack and pinion is to convert hydraulic pressure into mechanical force to assist the driver in turning the steering wheel. The rack steers the vehicle through the push of the hydraulic cylinder, thereby reducing the steering burden on the driver.
● Hydraulic oil: Hydraulic oil circulates in the system to transmit pressure, lubricate and cool.
What are the manifestations of power steering pump failure?
Power steering pump failure usually causes a series of obvious symptoms, which can help car owners to initially determine whether the problem comes from the pump. The following are common manifestations of power steering pump failure:
Heavy steering wheel
If the power steering pump fails or its performance deteriorates, the pressure of the hydraulic oil cannot be effectively transmitted to the rack and pinion, and the driver will feel that the steering wheel becomes abnormally heavy, especially at low speed or parking. This phenomenon is usually caused by insufficient pressure due to wear or leakage inside the pump.
Steering wheel makes abnormal noises
When the power steering pump fails, it is usually accompanied by abnormal noises when the steering wheel turns. This sound may be a sharp "squeak" or a "click" similar to mechanical friction. The source of the abnormal noise may be the friction between the rotor inside the pump and the pump housing, or the slippage caused by the loose pump belt.
Poor flow of hydraulic fluid
A power steering pump failure can also cause poor flow of hydraulic fluid through the system. If the pump is not functioning properly, the hydraulic fluid may not be effectively delivered to the rack gear, resulting in insufficient system pressure. At this point, the owner may notice an abnormal hydraulic fluid level or a slow flow rate when checking the oil line.
Hydraulic fluid contamination
Wear of the power steering pump can cause metal shavings or other impurities to enter the hydraulic fluid, causing the hydraulic fluid to deteriorate. These impurities can accelerate further wear of the system and eventually lead to complete pump failure. During routine maintenance, if the hydraulic fluid is found to be darker in color or has obvious particulate matter, it may be a problem with the power steering pump.
Steering system overheating
A power steering pump failure can also cause the system to overheat. Because the pump is not functioning properly, the hydraulic fluid circulates less efficiently within the system, the heat dissipation effect becomes poor, and the system eventually overheats. An overheated system accelerates component wear and may even cause the hydraulic fluid to boil and leak.
What are the manifestations of rack and pinion failure?
The rack and pinion is a key component that converts hydraulic pressure into mechanical steering force. Its failure manifestations are somewhat similar to those of the power steering pump, but it also has its own unique symptoms. The following are common symptoms of rack and pinion failure:
Steering sluggishness
Worn or damaged rack and pinion can cause the steering system to react slowly or inaccurately. The driver may feel a noticeable gap in the steering wheel or a lack of response from the wheels when turning. This is usually caused by a loose fit between the rack and pinion or a failed seal inside the rack.
Difficulty in returning the steering wheel to center
Normally, the steering wheel should automatically return to the center position after turning, a process that relies on the normal operation of the rack and pinion. If the rack and pinion fails, returning the steering wheel to center may become difficult or unnatural, and the driver may need to pull the steering wheel back to its original position with force. This phenomenon is usually caused by increased resistance inside the rack or poor meshing of the pinion.
Mechanical noise during steering
Rack and pinion damage is often accompanied by noticeable mechanical noise, especially during steering. Poor meshing of the pinion or wear inside the rack may cause a "clicking" sound or metal friction sound. These sounds are usually lower and heavier than the abnormal sound of the power steering pump.
Hydraulic fluid leakage
If the seal inside the rack and pinion is damaged, hydraulic fluid will leak from the system. The location of the leak is usually at both ends or joints of the rack, which will not only cause the loss of hydraulic oil, but also cause a significant decrease in the performance of the steering system.
Abnormal vehicle steering
A rack and pinion failure may cause the vehicle to have abnormal steering behavior during driving. For example, the vehicle may automatically deviate to one side without turning the steering wheel, or fail to maintain a stable driving route after turning. These abnormal phenomena are usually caused by wear of the rack and pinion or misalignment of internal components.
How to distinguish between power steering pump and rack and pinion failure?
Although the failure manifestations of power steering pump and rack and pinion overlap, through careful observation and testing, car owners can still preliminarily distinguish the root cause of the problem.
Check the status of the hydraulic oil
When the power steering pump fails, the hydraulic oil often deteriorates, darkens in color or contains metal chips. Rack and pinion failures usually do not directly cause hydraulic oil contamination. If an abnormality is found when checking the hydraulic oil, the problem is likely to be with the power steering pump.
Observe the steering wheel's turning resistance
When the vehicle is stationary, slowly turn the steering wheel and feel the change in resistance. If the resistance is uniform but large throughout the entire rotation process, the problem may be with the power steering pump; if the resistance is uneven or the steering wheel is stuck, the rack and pinion are more likely to be faulty.
Listen to the source of the abnormal noise
Although both failures will cause abnormal noise, the nature of the abnormal noise is different. The abnormal noise of the power steering pump is usually sharp and accompanied by the engine running. The abnormal noise of the rack and pinion is dull and more obvious when turning. By listening to the source and type of the abnormal noise, you can preliminarily determine the faulty component.
Perform a pressure test
If the owner has professional equipment, you can perform a pressure test on the hydraulic system. When the power steering pump fails, the pressure in the system is usually lower than the normal range. Rack and pinion failure will not significantly affect the pressure of the system, but it will affect the mechanical response of the steering.
Check the steering response
Power steering pump failure usually causes a heavy feeling throughout the steering process, especially at low speeds. Rack and pinion failure will affect the accuracy and sensitivity of the steering, and may cause the steering wheel to fail to automatically return to the center after turning or become sluggish when turning.
How to deal with power steering system failures?
Once the source of the problem is determined, whether it is the power steering pump or the rack gear that is faulty, it should be repaired or replaced as soon as possible. Delayed processing may lead to more serious failures and even affect driving safety. If it is confirmed that the power steering pump or rack gear is faulty, it should be promptly inspected and replaced at a professional repair shop. Do not delay processing, otherwise it may cause the entire system to fail or even cause danger.
Secondly, the power steering system requires regular maintenance, especially the inspection and replacement of the hydraulic oil. Keeping the hydraulic oil clean and at the proper level can extend the service life of the system and reduce the probability of failure. In addition, avoiding long-term steering when the vehicle is stationary and avoiding violent steering operations can help reduce the burden on the power steering system and extend its service life.
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