Power steering: types, disadvantages and advantages

Various power steering assists reduce the amount of physical effort required to turn the steering wheel, making driving less tiring and more comfortable. In addition, thanks to the presence of power steering, maneuverability is improved, and in the event of a tire puncture, it is easier to keep the car on the road and avoid an accident.

Although passenger vehicles can do without amplifiers, they are installed on most cars produced in our time. But driving a truck without power steering would turn into hard physical labor.

Types of power steering

As we already wrote, today's cars, even in the basic configuration, are equipped with such a necessary element as a power steering. The classification of aggregates is discussed in more detail below. All of them have a different structure, scheme, purpose, principles of operation and application.

There are three main types of power steering:

• hydraulic (GUR);
• electrohydraulic (EGUR);
• electric (EUR);
• mechanical.

Hydraulic power steering

Hydraulics began to be used in steering in the middle of the last century and still has not lost its relevance. Power steering can be found on many modern passenger cars.

The heart of the power steering is a pump, which is driven by a belt or chain drive from the engine crankshaft. The power steering pump creates a pressure of about 100 atmospheres in a closed hydraulic system.

The working fluid (oil) pumped by the pump is fed through the fitting to the distributor. Its task is to redistribute the fluid depending on the turn of the steering wheel.

The power hydraulic cylinder with a piston (steering rack) acts as an actuating device.

GUR advantages:

• steering comfort;
• a significant reduction in the effort required to rotate the steering wheel;
• to turn the wheels to the required angle, you need to turn the steering wheel less;
• if the wheel is damaged, it is easier to avoid departure from the track;
• in the event of a hydraulic booster failure, vehicle control will remain.

Power Steering Disadvantages:

• the amplifier works only when the engine is running;
• dependence on engine speed;
• since the pump is driven by the engine, this increases fuel consumption;
• holding the steering wheel in one of the extreme positions for a long time can cause severe overheating of the working fluid and failure of other elements of the system;
• in general, the hydraulic system is quite bulky and requires periodic maintenance.

Electro-hydraulic power steering

The principle of operation of the EGUR is the same as that of the hydraulic booster. The difference is that here the pump is driven by an electric motor, which is powered by a generator.

This allows you to reduce fuel consumption compared to power steering.

The electronic control system adjusts the force depending on the speed. This ensures ease and accuracy of maneuvering not only at high but also at low speeds, which is impossible when using a conventional hydraulic booster.

Disadvantages of EGUR:

• the system may fail if the steering wheel is held in the extreme position for a long time due to oil overheating;
• higher cost compared to power steering;
• poor contact in the electrical wiring or a malfunction of the control unit can lead to the cessation of the operation of the EGUR. The situation itself is not so critical, but a sudden sharp decrease in vehicle control while driving can cause panic in an unprepared driver.

What is better GUR or EGUR?

As already mentioned, EGUR has a separate control module. The trouble is that it is combined into a single assembly unit with the pump electric motor and its hydraulic part. On many age machines, the tightness is broken and moisture or even the oil itself gets into the electronics. This happens imperceptibly, and when it comes to obvious problems in the operation of the amplifier, it is too late to try to repair something. Expensive items will have to be replaced.

On the other hand, such a scheme with its own control unit, unlike the classic power steering, has an important plus - a kind of protection. If for some reason a large oil leak occurs from the system, then it will turn off the pump itself, preventing its sudden death due to dry running. As in the case of a classic hydraulic booster, any loss does not entail wear of the elements in the rail itself. Therefore, there is no definite answer to this question.

Electric power steering

The cumbersome and troublesome hydraulics are completely absent here. Accordingly, there are no inherent power steering shortcomings.

The EUR consists of an electric motor and a control unit.

How does electric power steering work? The sensor monitors the angle of rotation and the speed of rotation of the steering wheel and sends a signal to the electronic control unit. The processor analyzes the information from the sensor, compares it with the speed of the car and issues a control signal to the electric motor. The motor moves the steering rack accordingly.

Advantages of EUR:

• compactness;
• economy;
• low cost of EUR;
• no dependence on engine speed;
• operation does not depend on the ambient temperature;
• ease of adjustment.

Thanks to these positive qualities, the EUR is increasingly being installed on modern cars.

The main disadvantage The EUR is its low power, which depends on the power of the generator. This makes it very problematic to use the EUR on SUVs, and even more so on trucks.

Mechanical power steering

Mechanical power steering consists of a set of various gears in a housing. The effect of strengthening and facilitating control using such a mechanism is to change the gear ratio of rotation. Currently, this type is not used due to the complexity and unreliability of the design, as well as due to the increased noise level during operation.

Possible problems with power steering

Usually the power steering works quite reliably and does not cause serious trouble to car owners. Of course, nothing is eternal and sooner or later the hydraulic booster also fails. But many problems can be fixed on your own.

Most often there is a leak of the working fluid. It usually leaks at the points where the pipes are connected to the fittings, less often the pipes themselves crack.

If jolts or vibration are felt when turning the steering wheel, it is worth checking the condition of the pump drive belt. Adjust or replace if necessary.

The most vulnerable part of the power steering is the pump. When it turns out that it is faulty, the dilemma immediately arises: repair or replacement. If you have the desire, the necessary tools and experience in mechanical work, you can try to repair the pump yourself, although, of course, no one guarantees one hundred percent success.

Most often, the bearing fails in the pump. Often, when opening, defects in the grooves of the rotor and the inner surface of the stator are found. They need to be carefully sanded. The oil seal and rubber gaskets should also be replaced.

If it turns out that the valves are faulty, then they should be changed as a set, since they must match each other in terms of throughput.

If there is no possibility or desire to mess around with the repair of the power steering pump yourself, you can contact a car service. It is worth first finding out if there is a specialist of the required qualification in the chosen workshop and how much the repair will cost.

It might be better to just replace the pump. A new one is quite expensive, so it may be a viable option to purchase a refurbished one, which will cost less and last almost as long.

Possible problems with the EUR

You can check whether the EUR has completely turned off by comparing the efforts when turning the steering wheel with the engine stopped and running. If in both cases the same effort is required to rotate the “steering wheel”, then the amplifier is not working.

The first step is to check the wiring, the health of the generator, the integrity of the fuses, the reliability of the contacts. Then check the torque sensor and its contacts. If the speedometer also does not work, then the speed sensor should be checked.

If everything is in order with the contacts of the sensors, it is worth replacing the sensors themselves. The electronic control unit is easy to replace on your own, but you will have to contact service specialists to check it.

In some cases, a steering wheel ESD malfunction may manifest itself as unpredictable steering behavior while driving. In this case, you must immediately stop and turn off the EUR by removing the appropriate fuse. And then go to a car service for diagnostics.

Conclusion

The steering system plays a key role in driving a car. Any failures in its operation significantly affect the maneuverability and controllability of the vehicle.

In no case should you ignore the signs of a steering malfunction, as this can turn into a serious accident. It's not just your finances that are at stake. The life and health of you and other road users may be at risk.