GUR in a car: what is it and how it works

Modern driving is impossible without systems that make it easier to drive, especially at low speeds or when parking. One of the key technologies that ensure comfort and safety is power steeringThis is often referred to as the GUR. This system allows the steering wheel to be turned with a slight hand movement, even if the car is standing still or moving slowly, which is critical in dense urban traffic.

The principle of operation of the device is based on the creation of additional force, which is transmitted to the steering mechanism using a liquid under high pressure. Without this system, the driver would have to put considerable physical effort into maneuvering a heavy vehicle, which is not only tedious but also dangerous in emergency situations. Understanding how it works power steeringThis will help the owner of the car to notice the signs of its malfunction in time and avoid expensive repairs.

In this article, we will analyze the system in detail, consider the main components and assemblies, and also discuss the rules of operation that will prolong the service life of the mechanism. You will learn why the pump is buzzing, how to change the liquid correctly and how different types of amplifiers differ. This knowledge is necessary for every responsible driver who wants to maintain his or her own personal life. motor-car in good condition.

The device and principle of operation of the hydraulic system

The basis of any GUR system is a closed circuit, along which a special hydraulic fluid circulates. The main element that creates pressure in the system is pump. It is driven by a belt from the crankshaft of the engine and works constantly while the engine is running. The pump sucks the liquid from the expansion tank and pumps it under pressure into the distributor.

The key node that determines where to direct the flow of fluid to assist the driver is distributor Or a spool. It responds to the steering wheel rotation and redirects the oil flow to one of the cavities of the power cylinder. It is this cylinder, connected to the steering rack or pacifier, creates a physical force that pushes the wheels in the right direction.

To maintain stable operation of the system is used expansion-tankwhere the supply of liquid is located and where it is cooled and cleaned from wear products. Inside the tank is often a filter element that traps metal shavings and dirt. The entire system is connected by high and low pressure pipelines, which should maintain tightness.

⚠️ Warning: When checking the fluid level in the tank, never open the lid on a hot engine. The pressure in the system can be high and the hot oil can spill out, causing burns.

Let’s look at the main components that make up a typical power steering:

• 🛠️ Pump GUR: A lobe or rotary mechanism that creates operating pressure in the system.
• 🛢️ Extension tank: tank for storage and cooling of working fluid (oil).
• ⚙️ Distributor: The glossary mechanism that determines the direction of fluid supply.
• 🚗 Hydrocylinder: a piston mechanism that converts the pressure of a liquid into mechanical motion.

It is important to understand that all these elements work together, and the failure of one component affects the operation of the entire system. For example, liquid contamination can lead to a distributor jamming, and the wear of the pump belt can lead to a complete loss of gain.

Types of steering amplifiers

Technology is not standing still, and the classic hydraulic amplifier today has several modifications and alternatives. The most common option remains the classic GUR, where the pump is driven by a belt transmission from the internal combustion engine. It is a reliable and time-tested system, but it has a drawback: it consumes engine power continuously, even when no boost is needed.

A more modern version is the electrohydraulic amplifier (EGUR). In such a system, the pump is not driven by a belt, but by a separate electric motor. This allows the pump to be turned on only at the time of steering, which saves fuel and reduces the load on the power unit. The electronics itself regulates the pump performance depending on the vehicle’s speed and steering angle.

The fully electric analogue is electric power steering (ERR)where the hydraulic fluid and pump are completely absent. Here, the force is created by an electric motor mounted on the steering shaft or rack. EUR is considered more environmentally friendly and economical, but many drivers note less “live” feedback compared to classic hydraulics.

A comparison table will help you understand the difference between the main types of systems:

Characteristics	Classic GUR	Electrohydraulic (EGUR)	Electrical booster (ERM)
Power source	Engine (belt)	Electric motor	Electric motor
Fuel consumption	Above (constant load)	Medium (work as necessary)	Minimum
Service	Liquid replacement, belt.	Replacement of fluid, electronics diagnostics	Minimum
Feedback	Great, natural.	Good, customizable.	Depending on the settings, it can be artificial.

The choice of system depends on the class of car and the preferences of the manufacturer. Heavy SUVs and trucks are often equipped with classic hydraulic-amplifier Because of its reliability and ability to withstand huge loads.

The main signs of failure of the GUR

Any mechanical system is subject to wear and power steering is no exception. The driver may notice the first symptoms of a problem long before the system fails completely. One of the most common signs is the appearance of extraneous sounds when the engine is running or while the steering wheel is rotating. A hum, whistle, or howl usually indicates problems with the pump or low fluid levels.

If you feel that the steering wheel is turning heavier than usual, or the steering wheel force is changing unevenly (tight, then light), this is an alarm. This behavior often indicates suffocation of the system, wear of the internal components of the pump or problems with the pump. distributor. Ignoring these symptoms can lead to a jamming of the steering.

A visual examination can also reveal problems. Pay attention to the condition of the pipes and connections under the hood. The presence of oily spots or subtricks of reddish liquid on the asphalt after parking indicates the depressurization of the system. Leaks can occur through pump coils, rack cuffs or cracks in high-pressure hoses.

⚠️ Warning: If you hear a sharp pop or a strong crackle while driving and the steering wheel starts to rotate with great effort, stop immediately. This can mean breaking the pump drive belt or breaking its internal elements.

List of the main symptoms that require diagnosis:

• 🔊 Extraneous noise: A hum or howl when turning the steering wheel into extreme positions.
• 🏋️ Increased effort: The steering wheel became "heavy", especially at low speeds.
• 💧 Leaks: The appearance of puddles of liquid under the front of the car.
• 🌪️ Foaming: The liquid in the tank foams, which indicates air.

Timely response to these signs allows you to eliminate the malfunction at an early stage, replacing, for example, only the osteoils or belt, instead of buying a new pump assembly.

Diagnostics and system maintenance

Regular maintenance is the key to a long life power steering. First of all, it is necessary to monitor the level and condition of the liquid in the expansion tank. The check should be carried out on a cold engine or after a short work, focusing on the MIN and MAX tags. If the level is constantly falling, then there is a leak somewhere that needs to be found and fixed.

Particular attention should be paid to the quality of the working fluid. Over time, the oil loses its properties, darkens and is saturated with wear products. The dirty liquid acts as an abrasive, breaking down friction vapors in the pump and distributor. Manufacturers recommend changing the liquid GUR every 60-80 thousand kilometers or once every 3-4 years, even if the mileage is less.

An important element of maintenance is to check the tension of the pump drive belt. A too weak belt will slip, causing a squeal and insufficient pressure in the system. An overstretched belt will put extra strain on the pump bearings and can cause them to fail quickly. The tension must comply with the manufacturer's recommendations motor-car.

How to check the condition of the liquid visually?

Take a transparent syringe and draw some liquid from the tank. Put it on a white napkin. If the liquid is transparent and has a red or green tint, it is normal. If the color is black or brown, and the smell resembles a burnt one, an urgent replacement is required. The presence of metallic shine indicates wear of the metal parts of the pump.

When replacing fluid, it is important to pump the system properly to remove air. To do this, usually lift the front of the car, unscrew the lid of the tank and several times smoothly turn the steering wheel from the extreme left position to the extreme right, without starting the engine. Then the procedure is repeated with the engine running, but not holding the steering wheel in extreme positions for more than 5 seconds.

Operational rules and typical errors

Many drivers do not think that their driving habits directly affect the resource of the GUR system. The most common and harmful mistake is to keep the steering wheel in the extreme position for more than 5-7 seconds. At this point, the pressure in the system reaches a maximum, since the liquid does not circulate, and the pump operates in overload mode. This leads to overheating of the oil and accelerated wear of the oil glands.

Another mistake is the sharp throw of the steering wheel after the turn. When you let go of the steering wheel, it tends to return to zero position under the influence of the elasticity of the tires and the kinematics of the suspension. If at this moment abruptly let go of the steering wheel, a hydraulic shock occurs in the system, which can damage the distributor or lead to the leakage of glands. The steering wheel must be returned smoothly, controlling its movement.

Using the wrong fluid can also be fatal to the system. Different types of oils (mineral and synthetic) may not be compatible. Mixing them can lead to the formation of sediment, which will clog the thin channels of the distributor. Always use the liquid recommended by your manufacturer. motor-car.

Typical operating errors also include:

• 🚫 Long simple: If the car is long standing without movement, the oils may dry out.
• 🚿 Pressure wash: A jet of water under high pressure can damage the anthers of the reiki, and moisture will get there.
• 🛑 Driving with a malfunction: Ignoring the hum or leak leads to a complete failure of the system.

Frequently Asked Questions (FAQ)

Why does the GUR only hum on the cold?

A cold engine hum is often associated with high fluid viscosity at low temperature or wear of the pump blades. Also, the reason may be in the sucking of air through microcracks in the hoses, which hot expand and seal. If the hum does not pass after warming up, it is worth checking the condition of the liquid and the tension of the belt.

What liquid to pour in the GUR, if the color is mixed?

The color of a liquid (red, green, yellow) is not always an unambiguous indicator of its composition, although often red is ATF (automatic fluid), and green is a special hydraulic fluid. They can only be mixed if they are compatible. It is strictly forbidden to mix mineral and synthetic liquids.Even if the colors match. Better to flush the system completely.

Can I drive if I completely refuse to go to the GUAR?

You can go, but it will be difficult and dangerous. The steering wheel will become very heavy, especially at low speeds. However, if the pump jams, the belt may break, which on some cars will cause the engine to stop or overheat (if the belt is one). Therefore, you should continue the movement only to the nearest service, taking extreme caution.

How often should I change the fluid in the hydraulic booster?

The optimal replacement interval is every 60,000 km of run or every 3 years. However, when driving actively in urban conditions or towing trailers, the interval is better to reduce to 40 000 km. The condition of the liquid must be checked visually at each maintenance of the car.