If you are an experienced motorist, then you probably know what a steering rack is and why it should be constantly in working order. But if you are a beginner, knowledge of the steering rack will probably come in handy. In the article, we will consider what types of this mechanism are, how to determine a breakdown and what you will have to face in this matter.
Rack and pinion steering is the correct name for the part of the car that we are considering. Although the common expression of the steering rack has stuck for a long time and everyone understands what is at stake. This mechanism converts the rotation of the rudder shaft into left-right movement of the rods. And they, in turn, transmit power to steering knuckles front wheels. In other words, the steering rack is a transitional link between the driver who turns the steering wheel and the wheels that turn. Now you yourself understand how important the performance of this device is.
On the other hand, the rack is a piston rod, the body of which is the power steering cylinder. The body contains a spool that distributes the fluid flows into the first or second cylinder cavity. Depending on which direction the driver turns the steering wheel, the side with the fluid that is under pressure there will also change.
The steering rack device also depends on the type of mechanism. The mechanical form is the simplest and most common. It can be installed on both front-wheel drive vehicles and rear-wheel drive vehicles.
In this case, the wheels turn directly due to the efforts made by the driver. And in order to reduce them as much as possible, a rail containing a variable subordinate number can be used.
The size of the steering clearance is very important for the good and correct operation of the car, and this indicator directly depends on the condition of the steering rack.
Therefore, we will consider the device of the mechanical section. In such a mechanical mechanism, the teeth of the rack change their pitch from the center to the edges. Therefore, when driving at high speed, the steering wheel becomes a little heavier and its maneuverability decreases. And on the road at low speed, for example, when parking, the steering wheel turns a little easier (since there is a smaller subordinate number).
The first domestic car with such a device is the VAZ-2110. Drivers considered it a big plus that when turning, due to the mechanical rack, the steering wheel automatically became in the initially level position. There was no need to make an effort to return after the turn wheel to its original position, it was enough just to let it go.
Hydraulic rack device
How is the hydraulic steering rack structured? This question can be asked by the drivers of new cars in which the hydraulic booster has been introduced. The most basic difference from the mechanical type is that the power steering is present here and it gives ease of control and its sharpness. 
If we consider the structure of a hydraulic mechanism with a rack, then it consists of:
- Entrance.
- Spool bushings.
- Dust cap.
- Retaining ring.
- Spool oil seal.
- Spool.
- Bearing.
- Rod oil seal.
- The back.
- Rail stock.
- Retaining ring.
- Back seal.
- Piston rod.
- Stem bushings.
- Clamp nuts.
- Spool nuts.
- Spool plugs.
- Spool worm.
- Bypass tubes.
- Exit.
Whatever version of the steering rack is on the car, it is important to listen to its work and identify errors that are present. It can be knocking, creaking, whistling in the steering gear. And every driver should be alerted by these sounds. Even if they pass one-time, something is broken in the work - contact a specialist or look at the problem yourself.
Very often, to eliminate unpleasant sounds of a car, it is enough to lubricate all parts with oil or add liquid to a mechanical device. This will keep the machine working for many more years without use. overhaul... It is better to fix small problems right away than they turn into big problems. Take care of your car and it will serve you well and for a long time!
Video " How to replace the steering rack "
The recording shows step-by-step instruction to replace the steering rack. Watch this video and you can easily repeat all the steps on your car.
Nowadays, it is difficult to imagine a car without power steering. The amplifier can be electric (), hydraulic (power steering) or electro-hydraulic (). However, power steering remains the most common type at the moment. It is designed in such a way that even if it fails, the ability to drive a car will remain. In this article, we will analyze its main functions and find out in detail what it consists of.
Functions and purpose of power steering
Steering rack with hydraulic boosterHydraulic Power Steering (Power Steering) is a steering element in which additional steering force is generated by hydraulic pressure.
For cars, the main purpose of power steering is to provide comfort. Driving a vehicle equipped with hydraulic power steering is easy and convenient. In addition, the driver does not need to make a full five or six turns in the direction of the turn to make a maneuver. This is especially true when parking and maneuvering in tight spaces.
Maintaining control of the vehicle and mitigating the shock transmitted to the steering wheel as a result of a collision of the steered wheels on bumps in the road is also an important function of the power steering.
Requirements for the hydraulic booster
For the efficient operation of the power steering, the following requirements are imposed on it:
- system reliability and quiet operation;
- ease of maintenance and minimal device size;
- manufacturability and environmental safety;
- small turning moment on the wheel with automatic return to neutral position;
- ease and smoothness of steering;
- ensuring kinematic tracking action - correspondence between the angles of rotation of the steered wheels and the steering wheel;
- ensuring the power tracking action - proportionality between the forces of resistance to turning the steered wheels and the effort on the steering wheel;
- the ability to drive a car when the system fails.
Power steering device
The main components of the power steering Power steering is installed on any type. For passenger cars, the rack and pinion mechanism is most widespread. In this case, the power steering scheme is as follows:
- reservoir for working fluid;
- oil pump;
- spool valve;
- hydraulic cylinder;
- connecting hoses.
Power steering reservoir
Power steering reservoir A filter element and a dipstick for monitoring the oil level are installed in the reservoir or reservoir for the working fluid. With the help of oil, rubbing pairs of mechanisms are lubricated and force is transferred from the pump to the hydraulic cylinder. A mesh in the tank serves as a filter from dirt and metal chips that arise during operation.
The liquid level inside the tank can be checked visually when the tank is made of translucent plastic. If the plastic is opaque or a metal tank is used, check the fluid level with a dipstick.
In some vehicles, the fluid level can only be checked after a short period of engine operation, or by rotating the steering wheel several times in different directions while the vehicle is idling.
Special notches are made on the probes or reservoirs, both for a "cold" engine, and for a "hot" one that has been running for some time. Also, the required liquid level can be determined using the "Max" and "Min" marks.
Power steering pump
Power Steering Vane Pump It is necessary so that the required pressure is maintained in the system, and oil is circulated. The pump is mounted on the engine block and driven by a pulley crankshaft using a drive belt.
Structurally, the pump can be of different types. The most common are vane pumps, which are characterized by high efficiency and wear resistance. The device is made in a metal case with a rotor with blades rotating inside it.
In the process of rotation, the blades capture the working fluid and supply it under pressure to the distributor and then to the hydraulic cylinder.
The pump is driven by the crankshaft pulley, so its performance and pressure depend on the number of engine revolutions. To maintain the required pressure in the power steering, a special valve is used. The pressure that the pump creates in the system can reach up to 100-150 bar.
Depending on the type of control, oil pumps are divided into variable and fixed:
- variable pumps maintain constant pressure by changing the productive part of the pump;
- constant pressure in unregulated pumps is maintained by a pressure reducing valve.
The pressure reducing valve is a pneumatic or hydraulic choke that acts automatically and controls the oil pressure level.
Power steering distributor
Schematic device of the distributor The power steering valve is mounted on the steering shaft or on the elements. Its purpose is to direct the flow of the working fluid into the corresponding cavity of the hydraulic cylinder or back into the tank.
The main elements of the distributor are the torsion bar, the rotary valve and the distributor shaft. The torsion bar is a thin, springy metal bar that twists under the action of a torque. The spool and the distributor shaft are two cylindrical parts with fluid channels inserted into each other. The spool is connected with the steering gear, and the distributor shaft with cardan shaft, that is, with a steering wheel. The torsion bar is fixed at one end on the distributor shaft, its other end is installed in the rotary valve.
The valve can be axial, in which the spool moves translationally, and rotary - here the spool rotates.
Hydraulic cylinder and connecting hoses
The hydraulic cylinder is built into the rack and consists of a piston and a rod that moves the rack under the action of fluid pressure.
The scheme of fluid circulation in the hydraulic booster Connecting hoses high pressure provide oil circulation between the distributor, hydraulic cylinder and pump. Oil from the reservoir to the pump and from the distributor back to the reservoir flows through low pressure hoses.
The principle of operation of the power steering
Consider several modes of operation of the hydraulic booster when turning the wheels in any direction:
- The vehicle is stationary and the wheels are straight. At the moment, the hydraulic booster does not work and the liquid is simply pumped through the system (from the tank to the distributor and vice versa).
- The driver starts to turn the steering wheel. The torque from the steering wheel is transmitted to the distributor shaft and then to the torsion bar, which begins to twist. The rotary valve does not rotate at this moment, since it is prevented from doing so by the friction force that prevents the wheels from turning. Moving relative to the spool, the distributor shaft opens a channel for fluid to enter one of the cavities of the hydraulic cylinder (depending on where the steering wheel is turned). Thus, all pressurized fluid is directed to the hydraulic cylinder. The liquid from the second cavity of the hydraulic cylinder enters the drain line and then into the tank. The liquid presses on the piston with the rod, due to which the wheels move and turn.
- The driver has stopped turning the steering wheel, but continues to hold it in the turned position. The steering rack, moving, rotates the rotary valve and aligns it with the distributor shaft. At this moment, the distributor is set to the neutral position and the liquid again simply circulates through the system, without doing any work, just like when the wheels are in a straight line.
- The driver "unscrewed" the steering wheel to the extreme position and continues to hold it. This mode is the most difficult for the hydraulic booster, since the valve cannot return to the neutral position, and all fluid circulation occurs inside the pump, which is accompanied by an increased noise of its operation. But once you let go of the steering wheel, the system will return to normal.
The scheme of the hydraulic booster The power steering is arranged in such a way that if it fails steering will continue to work and the ability to drive the car will remain.
Frequency of fluid replacement in power steering
In theory working fluid can be used for the entire life of the vehicle, but it is recommended to periodically change the oil.
The replacement time depends on the intensity of vehicle operation. With an average annual mileage of 10-20 thousand km, it is enough to change the oil every two to three years. If the machine is used more often, then the fluid change must be done more often.
As a result of the operation of the hydraulic booster, the temperature of its elements rises. Due to this, the oil is also heated, which leads to a deterioration in its physical properties. If, when checking the condition of the liquid, foreign particles or the smell of burning oil are noticed, then it is time for a replacement.
09.03.2017
Experienced motorists know what a steering rack is and how important it is to keep it in working order. The correct name for this unit is the rack and pinion steering gear, but it did not take root among the people. The essence of the mechanism is quite simple - to convert the steering wheel turn into a left-right movement of the rods (for the front wheels this is a horizontal deflection), which redirect the force to the front wheels through the steering knuckles.
In simple terms, the steering rack is an intermediate link between the person sitting at the steering wheel and the wheels being steered. It is not surprising that the performance of such a mechanism must be flawless. How does the steering rack work?
Principle of operation
The specified mechanism from the structural point of view is a rod with a piston. Its base acts as a power steering cylinder. There are two cavities in the cylinder, which are filled with liquid by means of its distribution by a spool located in the body. Taking into account the steering side (left or right), the side where the fluid is under pressure also changes.
Today, there are 3 types of rack and pinion mechanisms in cars, which differ in the principle of operation:
- mechanical;
- hydraulic;
- electric.
Mechanical rail device
This type is characterized by its structural simplicity and efficiency. The principle of operation of the steering rack is the same as described above, and the rotation of the wheels is ensured by the applied force from the driver. To reduce the load on the hands, manufacturers are completing new vehicle models with a variable ratio rack.
Simply put, the pitch between adjacent teeth of the rack is adjusted from the edges to the middle. As a result, with an increase in driving speed, maneuverability decreases, and it becomes more difficult to control the steering wheel. Even a child can turn the steering wheel at minimum speeds, due to the minimum gear ratio. Such a simple design has proven itself perfectly in domestic car VAZ-2110.
Hydraulic steering gear
The main difference between the power steering rack and the one discussed above is that the driver's physical efforts are increased due to the built-in hydraulic amplifier. With such a device, ease of control of the vehicle and its high maneuverability are provided, regardless of the driving speed. Almost all modern cars are equipped with such mechanisms.
High traffic safety is ensured by the power steering: it extinguishes small potholes and irregularities on the roadway due to the hydraulic booster. The driver's hands remain on the steering wheel without any jerking. Many owners of such vehicles complain that they do not "feel" their iron horse.
This disadvantage is partially offset by modern suspensions in combination with an electric hydraulic booster.
Electric mechanism
The principle of operation of the electrical mechanism is almost completely identical to the hydraulic one. Power unit at the same time, an electric motor integrated into the steering shaft, steering column or rack is protruding (considered the safest option). The option with an electric motor in the steering column did not find popularity due to its low structural reliability.
The steering rack is a mechanism that transfers the rotation of the steering wheel to the rotation of the wheels. The simplest device of this mechanism is a gear on the steering shaft, from which the steering rack pulls. But with the development of the automotive industry, more complex mechanisms have been developed. Today there are three types of steering racks: mechanical, electrical and hydraulic. They have a different device and mode of operation.
Steering rack device
All types of system have a similar structure: the rack has teeth that move along the steering column gear. These teeth have a gear ratio that is specially selected for the correct transmission of force. Some types contain additional devices to facilitate car control.
Mechanical steering rack device
This type of rail has the simplest device. The rotation of the wheels is carried out only by the effort of the driver. It consists of gears that work in the same way as a gearbox.
The system has two gear mechanisms: one is connected to the steering wheel drive, and the other to the wheel rods. They have a specific gear ratio that makes it easier for the driver. Even a small movement of the steering wheel is capable of deflecting the wheels from the horizontal axis. This is especially convenient when maneuvering in confined spaces: the driver can easily turn the steering wheel all the way and steer the wheels.
Power steering rack
On almost all new cars, in addition to the standard rail, power steering is installed - a power steering. It makes driving easy and enjoyable. It also helps to extinguish pits and bumps on the road - they do not hit the steering wheel, which makes driving safe.
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Power steering rack device: it consists of a pump in which the working fluid moves. When you turn the steering wheel, it presses on the piston with a rod, which is responsible for turning the wheels. In neutral steering position, all fluid returns to normal position.
The power steering rack first appeared on trucks that were difficult to manage. But with the development of technical progress, they began to install it on passenger cars.
Electric power steering rack
This type of mechanism has an electric motor to enhance the conversion of steering motion into wheel deflection. It is controlled by an ECU and special sensors.
There are three ways to mount this system: the motor is on the rail, the motor is built into the column, or the motor is on the shaft. The option with a built-in motor in the steering column is considered the most dangerous: if it fails, the car becomes uncontrollable.
Today this mechanism is considered the most progressive, since it has the highest efficiency of all types. It is easy to maintain: there is no need to top up the working fluid, there are no oil seals that could leak. It is also economical, while fluid constantly flows in the power steering, the electric motor starts only when the steering wheel rotates.
Scheme of work
It is not very difficult to understand what a rail is in a car. From the steering wheel goes steering column, which at the end has a gear with a gear ratio. In the timing gear, this pinion meets a pinion on the rack. Depending on the type of design, pistons with a working fluid or an electric motor with a control unit are located further. After that, the torque is transmitted to the steering rods to the wheels.
This is a simplified diagram of the device, which is necessary to understand the principle of operation. In fact, the steering rack consists of regulating elements: springs, bushings, stops.
Malfunctions
Any unit in the car can break down. This happens especially often on long runs. Over time, parts wear out and become unusable. But there may be other reasons for car breakdowns.
Causes of malfunction
The global reason why this mechanism can break down is the poor quality of the roads. Car enthusiasts are unable to improve it, but they can drive a car more attentively: bypass pits and bumps, slow down on a bad road, and not operate a city car in off-road conditions.
In bad road conditions not only the suspension can deteriorate, but also the oil seals and anthers of the steering mechanism can fail. And through the holes in them, road dust can get into the mechanism. Most often, it is she who is the cause of the breakdown of the gear mechanism.
Symptoms: Diagnostics
Do-it-yourself steering rack diagnostics suggests that the driver must pay attention to the slightest changes in driving. Signs of a defective steering rack:
Weighting the steering wheel in certain positions;
Knock on the rail;
Steering vibration;
Power steering fluid leak;
Incomplete return of the steering wheel to its original position;
The steering wheel rotation does not match the rotation of the wheels.
The most common symptom is knocking at the front of the vehicle. Diagnostics of the steering rack in a car service is the most obvious way out. Most likely, the master recognizes its breakdown and offers to replace it.
But remember that some breakdowns can be repaired. For example, if a mechanical type is installed on your car, the master can disassemble the device, find the breakdown and fix it. You just need to find a reliable technician and compare the price of repair and the cost of replacing the steering rack. It is worth it to repair the steering rack or not - decide for yourself, it depends on the type of device and its price.
Major malfunctions
There are two main signs of serviceability - knocking and fluid leakage. They can talk about many breakdowns, which a car service master will help you find. Possible malfunctions steering rack:
Surface knocking can occur due to damage to the anthers. In this case, the traction ends quickly fail and begin to knock. In this case, they are simply replaced with new ones.
Internal knocks can indicate a malfunction of the pistons or guide bushings. For diagnostics, you will need to disassemble the mechanism and identify a breakdown. Only a specialist can determine the knock on the steering rack and its character.
Also, a knock can talk about the development of parts on high mileage of the car. This breakdown cannot be repaired; the mechanism must be replaced with a new one.
Leaks can only occur on a power-assisted device. She says that the oil seals are out of order and need to be replaced. If a leak occurs, the rail should be disassembled and all parts inspected. If you have a question about what to do if the steering rack leaks, you should buy a repair kit and take it to a service for repair.
If it is impossible to turn the steering wheel with the EUR, this may be due to the failure of the electric motor.
If the steering wheel with power steering turns hard, this may indicate a pump malfunction.
How to distinguish a malfunction of a steering rack from a breakdown of a power steering
Faults in the power steering can be recognized by the characteristic symptoms:
Power steering disappeared under any conditions;
Gain disappears only when the engine is idling;
Extraneous noise when the amplifier is operating;
The working fluid is foaming.
If you have these symptoms, consult a professional who understands how the power steering rack works for troubleshooting.
Remember that prevention is The best way prevent malfunctions. To extend the life of this mechanism, simple rules should be followed:
Check the anthers regularly. If a crack or hole has formed on them, it is better to replace them immediately.
In winter, you first need to warm up the engine and only then start moving and turn the steering wheel. It is best to turn the steering wheel slightly from side to side in place to warm up the oil.
Slow down in front of pits and bumps and try to go around them.
Remember to change the power steering fluid.
Do not jump sharply from the spot, especially if the steering wheel is twisted all the way.
A steering rack is a mechanical device that transfers power from the steering gear to the wheels. The steering rack device looks complicated outwardly, but few masters understand internal mechanisms and know how to repair them. Therefore, in the event of malfunctions, you should find a good car service in order to troubleshoot the steering systems or change the entire mechanism.
Repair of steering racks is a complex process that a novice car enthusiast cannot cope with.
Features of steering racks on cars
For everyone modern machines install amplifiers to make it easier for the driver to drive. Plus, they provide safety in challenging environments. To ensure that the driver does not lose his sense of the road, manufacturers resort to modifications to the suspension.
Ford
Many car enthusiasts complain that steering racks often break on cars from this manufacturer. This applies to almost all models, but Ford Focus owners have a lot of problems. Some batches of this model had defective rails that were assembled on old equipment. They broke down already in the first thousand kilometers.
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Most of the models from this manufacturer have a hydraulic booster. On some modern versions, an EUR is installed.
Renault
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All Renault models are equipped with power steering. It does not cause problems with regular maintenance... We must not forget to change the power steering fluid, then it will last a long time. Remember to only use the fluid recommended by the manufacturer because it works best with these vehicles.
Toyota
Toyota installs a hydraulic booster on its models. It makes it easier to drive a car and is responsible for the comfort of the trip. It works stably on these cars and rarely breaks down.
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This brand produces cars in the price category above the average, so modern models are equipped with a more expensive analogue - an electric booster. But his weakness is that he is afraid of damp weather. You should not drive such cars through deep puddles, so as not to damage the electronics of the car.
Opel
Power steering is installed on most models of this brand. There are usually no problems with him, but some motorists complain about the pumps in the Opel Vectra. It is difficult to repair, so it is recommended to replace it with a new one.
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In modern Opel Astra, they put EUR. Judging by the reviews of motorists, it can turn off when turning and does not work well in wet weather. This could be due to faulty sensors or poor wire connections. Usually, when these problems are eliminated, the electric amplifier works stably.
Lada Kalina: renovation
There are two generations of Kalina, both have an electric amplifier. It is a conventional mechanical rail, which is amplified by an electric motor. It is easy to install, therefore it is present in all trim levels of this model. But its minus is that it turns on at both low and high speeds.
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Unfortunately, the EUR also breaks down on cars with high mileage, and on new machines. Most often, the reason lies in the control unit. At the same time, the light on dashboard and the steering wheel stops turning. If this happens suddenly, stop and turn off the power to this unit. Then you can get to the service, where they will remove and change the unit.
WHA
The abbreviation VAZ most often means classic models - from "penny" to "twelfth". They are equipped with a conventional mechanical rail without amplifiers. Problems with it can begin only due to mechanical damage to the anthers or physical wear of parts.
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Today VAZ produces models with hydraulic and electric boosters. This is required by the development of technology and customer requests. Their breakdowns are similar to breakdowns on other cars, most often they appear at high mileage.
Power steering (hereinafter referred to as power steering) in a car is a system designed to reduce the efforts applied to the steering during a maneuver. Initially, such systems were equipped with agricultural and cargo vehicles.
From the beginning of the 70s, power steering began to be installed on cars... Not the least role in this was played by the fact that women increasingly acted as drivers.
In addition to providing comfort while driving, the power steering allows you to:
- reduce the diameter (dimensions) of the steering wheel;
- change the gear ratio of the steering shaft-rack system, providing greater maneuverability during a turn;
- automate the vehicle handling system.
Considering that steering is the second driving safety factor after brake system, high requirements are imposed on reliability, information content, other parameters of power steering. Special attention should be paid to the operation and maintenance of this system.
Types of power steering
Initially, power steering was installed on passenger vehicles, made according to a scheme similar to amplifiers installed on heavy vehicles. They have a significant disadvantage: with an increase in vehicle speed, a smaller steering angle and applied force are required to carry out a safe maneuver. At high speed, the road-steering feedback is significantly reduced, the driver ceases to "feel" the road. In slippery conditions, the vehicle may become unstable.
To eliminate this problem, a rail with variable gear ratio. Such a rail is installed on the VAZ 2110. It has a large gear ratio at small steering angles. This usually corresponds to high speeds and small cornering angles where little effort is required. Ratio decreases towards the "edges", that is, at large angles of maneuvering, which are possible at low speed. This design did not eliminate all handling problems.
Video - types of steering racks, what is the difference between power steering and EUR:
Manufacturers have developed electrohydraulic power steering by adding to the standard circuit a solenoid valve with electronic system management. EGUR combines to the maximum extent the information content of the steering wheel and comfortable driving conditions.
In some car models, the power steering pump is rotated by an electric motor drive. In such cases, the hydraulic booster works even when the engine is not running.
V modern cars increasingly install electric power steering... Their significant drawback is complete dependence from the serviceability and reliability of the electronics. In the event of a failure of any of the electronic components, drives, even a fuse, the efficiency of the electric power steering becomes zero, controllability deteriorates sharply.
How does power steering work?
The basic diagram of a power steering rack device is shown in the figure:
While the engine is running internal combustion the drive of the oil pump of the power steering, kinematically connected to the crankshaft, rotates. With the steering wheel in the center position, oil is recirculated through the hydraulic system effortlessly through a non-return valve. The torsion bar, which acts as a follower, responds to the steering wheel turn. It drives the valve spool. It communicates the main delivery channel with the right or left cavities of the power cylinders. The latter help turn the wheels of the car.
In the extreme positions of the steering wheel, the safety valves prevent excessive pressure in the system, bypassing the oil in the recirculation channel.
In the electrohydraulic power steering, an electrovalve is installed, which is controlled by an electronic control unit (ECU). The power steering ECU, guided by the readings of the sensors for the steering wheel angle, vehicle speed, crankshaft, adjusts the valve closing. Thus, depending on the speed of the car, other indicators, the degree of power steering amplification is regulated, the information content of the steering is controlled.
Malfunction symptoms and possible causes
During the operation of the car, the following signs indicate the malfunctioning of the power steering:
1. Steering wheel recoil... Usually occurs when the power steering pump malfunctions or a weak drive belt tension.
2. Great effort when turning the steering wheel... The reason may be: low level liquids, worn out power steering pump, airiness of the system.
3. Great effort in the mid-rudder area... The main reason is the mechanical wear of the rail.
4. Increased effort to one side... Reason: Worn oil seals.
5. Steering quickly takes effort. Possible reasons: airiness, pump malfunction, small idle speed engine.
6. Noise... Causes: low fluid level, leakage in the system.
7. Vibration... Often happens when tires are damaged, brake system malfunctions. In the power steering system, air may enter the hydraulics.
The main malfunctions of steering racks with hydraulic booster, their elimination and repair
During operation, the power steering rack system requires constant inspection, maintenance and repair (if necessary). The most common system failures include:
1.Flow
Seal leakage is most often caused by corrosion in case of water ingress on the shaft, which, as rust appears on it, destroys the working surface of the oil seal. Such a malfunction is possible when the anther is destroyed, caused by mechanical stress or natural wear and tear.
Repair consists in restoring the integrity of the shaft, removing traces of corrosion (usually the shaft is ground). After that, a new oil seal is installed with the appropriate fitting dimensions.
Leakage of hydraulic hoses is caused by high pressure in the system (100 atmospheres or more), wear of hoses, especially at the joints of rubber and metal elements of high pressure hoses. Usually a hose replacement is required, but there are workshops that repress the connections.
2.Knock
It can arise for reasons:
- breakage or erasure of the central tooth of the rack;
- wear of the support sleeve;
- malfunctions of the clamping rusks.
The rail tightening in case of wear of the central tooth does not give a result. The backlash may be less, but since the other teeth are less worn (increased wear of the central tooth is due to the fact that the steering wheel is in the middle position for more time), the steering wheel may not return from the extreme positions due to clamping.
Video - about the resource of the steering rack with the hydraulic booster:
Support bushings are severely destroyed when driving on uneven road surfaces. Most of the rack and pinion mechanisms of foreign cars are not designed for Russian roads.
3.Tight steering wheel
If the steering wheel only turns in one direction with effort, it is most likely that the O-ring in the distributor housing is allowing fluid under pressure to pass through. This can be the result of dirt or dust getting into the system, which makes grooves over time. The liquid does not enter the hydraulic cylinder, but goes directly to the expander reservoir. Repairs can be done by grinding the work area and replacing the O-ring.
If the steering wheel turns too tight to either side, there are several possible reasons:
- malfunction of the piston teflon ring;
- grooves in two chambers of the distributor;
- worn out working steam of the pump;
- breakage of the torsion.
To diagnose a specific malfunction, disassembly of the mechanism and diagnostics of units are required. In most cases, specialist assistance will be required.
Checking the operation of the power steering pump
To check the operation of the power steering pump, a special pressure gauge and adapter pads are required. Check sequence:
- an adapter block with a pressure gauge is installed in the gap hydraulic system outlet hose of the pump;
- the engine starts, idles for a couple of minutes;
- the steering wheel turns to the right and left several times to reach the operating temperature of the power steering fluid;
- the pump pressure is measured with the shut-off valve open, which must be at least 1500 kPa;
- for a short time ( no more than five seconds!) the shut-off valve closes;
- with the shut-off valve closed, the pressure must be at least 6500 kPa.
