The appearance of extraneous sounds during operation of the power steering is always a signal that the system is not functioning correctly. If you hear that power steering creaks when turning the steering wheel, this symptom cannot be ignored, as in the future this can lead to complete failure of the mechanism and loss of control of the car while driving. Drivers often confuse creaking, whistling and humming, but for diagnosis it is important to accurately determine the nature of the sound, as it indicates different components.
In most cases, the problem lies in weakened drive belt tension or a critically low level of working fluid in the tank. Hydraulic booster operates under high pressure, and even a slight leak or change in oil viscosity affects its acoustic background. In this article, we will look in detail at why noise occurs, how to carry out initial diagnostics, and what steps need to be taken to resolve the problem.
Diagnostics of the level and condition of power steering fluid
The first thing to check is if power steering pump hums or a characteristic creaking sound is heard, this is the level of working fluid in the expansion tank. Lack of oil causes turbulence and air to enter the system, which instantly causes noise and reduces the efficiency of the amplifier. The check should be carried out on a cold engine, focusing on the marks MIN and MAX on the container body.
However, not only the volume is important, but also the condition of the substance itself. Over time hydraulic oil loses its properties, darkens and becomes contaminated with wear products. If the fluid has acquired a black tint or metal shavings are visible in it, this indicates serious wear on the internal friction pairs of the pump or rack.
Often the reason that the system makes sounds is the use of the wrong type of fluid. Manufacturers recommend pouring different compounds into different cars, for example, ATF Dexron or specialized oils PSF.
- 🛢️ Check the color of the liquid: it should be transparent, red or green, without dark inclusions.
- 💧 Make sure that the level is strictly between the minimum and maximum risks.
- 🌡️ Pay attention to the smell: a burnt aroma indicates overheating and destruction of the oil structure.
⚠️ Attention: Never mix liquids of different colors and chemical bases unless you know exactly their compatibility. This can lead to the formation of sediment, which will instantly clog the filter mesh and damage the pump.
Before refilling, always wipe the neck of the tank with a clean rag to prevent dust and dirt from getting inside the system, since even a microscopic particle can damage the plunger pair of the pump.
Problems with the drive belt and its tension
If, when turning the steering wheel sharply in any direction, a piercing whistle is heard, which is quickly replaced by a squeak, most likely the problem lies in the belt drive. The belt that drives the pump pulley stretches over time and its tension weakens. At moments of peak load, when maximum pressure in the system is required, the belt begins to slip along the pulley.
Slippage causes strong heating of the rubber and the appearance of a characteristic sound. In addition, cracks, delaminations, or oil stains may appear on the surface of the belt. Oil getting on the belt is a common reason why power steering belt whistles, even if its tension is formally normal. Oil drastically reduces the coefficient of friction, making slippage inevitable.
The tension can be checked manually by pressing your finger on the longest span of the belt. The deflection should not exceed 10-15 millimeters, although the exact values depend on the make of the car and the type of belt.
- 🔍 Inspect the belt for cracks, abrasions and oil deposits.
- 📏 Check the tension: the belt should not be too loose or overtightened.
- 🛠️ Make sure that the pump and generator pulleys are in the same plane and have no play.
☑️ Power steering belt diagnostics
It is important to understand that an overtightened belt creates excess load on the pump shaft bearings, which can also cause humming and squeaking. Therefore, adjustments must be made carefully, in compliance with factory parameters.
Power steering pump malfunctions
The most expensive element of the system is the pump, and it is this that most often becomes the source of noise due to internal wear. If the fluid level is normal, the belt is tensioned correctly, and the sound persists, then the internal parts of the pump mechanism are likely worn out. The design uses bearings, rotor plates and a distribution disc, which are subject to normal wear.
When power steering pump hums, this often indicates wear in the shaft bearings or the appearance of scoring on the inner surface of the stator. In such cases, the pump stops creating the necessary pressure, and the steering wheel becomes “heavy,” especially at low engine speeds. The creaking noise in this case may come from a dry bearing that is no longer effectively lubricated due to impaired fluid circulation.
The pump can be diagnosed by measuring the pressure in the system using a special pressure gauge connected to the line gap. However, to initially determine the malfunction, it is often enough to listen to the operation of the unit through a technical stethoscope or a long screwdriver, placing your ear on the handle.
Power steering pump life
The average service life of a high-quality power steering pump is from 100 to 150 thousand kilometers. However, if you use low-quality fluid or do not replace the belt in a timely manner, this resource may be halved. Restoring the pump is possible, but requires high qualifications and the availability of a repair kit.
If a large amount of metal shavings is found in the liquid, this is a sure sign that the pump is “crushing.” In this case, simply changing the oil will not help, since wear products will quickly clog the new part.
Air in the system and airing
One of the most insidious causes of noise is air entering the hydraulic system. Air, mixing with liquid, forms an emulsion, which, when passing through narrow channels and valves, produces a characteristic gurgling sound or creaking sound. This phenomenon is often called cavitation, although technically it is just airing.
The reasons for air ingress can be different: from leaky connections and hoses to a low fluid level, at which the pump begins to capture air along with oil. Air can also enter the system after an unqualified fluid change or repair if the correct bleeding procedure was not carried out.
To fix the problem, you need to find the location of the leak and eliminate it, and then bleed the system. The procedure usually involves turning the steering wheel from full left to full right repeatedly with the engine running (but without holding the steering wheel in full position for long).
- 🔧 Check the tightness of all clamps on the high and low pressure hoses.
- 💨 Inspect the pump shaft seal for leaks through which air may be sucked in.
- 🔄 Carry out the procedure for pumping the system according to the vehicle manufacturer’s regulations.
⚠️ Attention: Holding the steering wheel in the extreme position for a long time while the engine is running leads to a sharp rise in pressure and overheating of the fluid. This can damage the seals and accelerate wear on the pump.
Worn steering rack and tips
The source of sound is not always located directly in the pump or tank. It often makes a creaking noise when turning the steering wheel. steering rack or steering components connected to it. Wear of the gear pair, wear in the cracks or damage to the boots can lead to the appearance of extraneous sounds, which the driver mistakes for a power steering malfunction.
If the boots are torn, dirt and water get inside the mechanism, washing out the lubricant. This leads to dry friction of metal surfaces, which causes squeaking. In power steering systems, the internal rack seals can also wear out, causing fluid leakage and noise.
It is more difficult to diagnose a rack than a pump, since it is hidden under the body and protected by screens. However, when rocking the steering wheel while parked or while driving, you can determine the presence of play or knocking noises, which often accompany a squeak.
| Symptom | Probable Cause | Elimination method |
|---|---|---|
| Whistle when starting and turning | Belt slippage | Tensioning or replacing the belt |
| Rumbling when cold | Thick oil or pump wear | Fluid replacement or pump repair |
| Creaking in the cabin | Friction of plastic or cardan | Lubricating or adjusting the steering column |
| Gurgling in the tank | Air in the system | Bleeding the system and searching for suction |
The creaking can come not only from hydraulics, but also from the mechanical part of the steering, so diagnostics must be comprehensive.
Noise elimination methods and prevention
Eliminating squeaking and humming directly depends on the identified cause. If the problem is with the belt, it will need to be replaced or tightened. If the fluid is to blame, make a complete replacement and flush the system. If the pump or rack wears out, expensive repairs or replacement of the entire unit may be required.
To prevent malfunctions, it is recommended to regularly check the condition of the drive belts and the fluid level. It is also important to use only those types of oils recommended by the vehicle manufacturer. You should not skimp on steering system components, since traffic safety depends on their serviceability.
If you notice that the steering wheel creaks or an extraneous sound appears, do not delay your visit to the service center. Timely detection of a malfunction at an early stage allows you to get by with minimal costs, for example, replacing the oil seal or belt, instead of buying a new pump.
- 🛡️ Replace power steering fluid every 60-80 thousand kilometers.
- 🚗 Avoid sharp turns of the steering wheel in place, especially when the car is cold.
- 🔧 Regularly check the tightness of hoses and connections under the hood.
Is it possible to drive if the power steering pump is humming?
You can drive with a humming pump only to the nearest repair place if the fluid level is normal and the steering wheel is turning. Long-term operation will lead to complete destruction of the pump, chips getting into the rail and costly repairs of the entire system.
What kind of liquid should I fill in if I don’t know what happened before?
If the type of fluid is unknown, the safest option is to completely flush the system and fill with new fluid recommended by the car manufacturer. Mixing different types of oils can lead to a chemical reaction and system failure.
Why does the squeak only appear when it is cold?
Creaking when cold is often caused by thickening of the liquid, which increases the load on the pump, or slipping of a cold, less elastic belt. After warming up, the viscosity changes and the sound may disappear.
Does belt quality affect noise levels?
Yes, high-quality belts have a special coating that prevents slipping and wear. Cheap analogues can creak even with the correct tension due to the poor quality of the rubber compound.