How to check a shock absorber for performance when purchasing

How to check shock absorbers for serviceability and performance?

Good day, dear motorists! Before we take a closer look at the issue of how to check the performance of a shock absorber, some not entirely good news.

Naturally, news for those who are not yet aware of the matter. The method of checking the serviceability of shock absorbers by rocking the body of your car has sunk into oblivion.

Once upon a time, on old classic models with previous models and types of shock absorbers, by swaying the body it was possible to determine whether the shock absorber was working or not. The complex design of a modern car suspension will not allow you to make an objective conclusion about the serviceability of the shock absorber by eye.

Then a reasonable question arises - how to check the serviceability of the shock absorber.

What can you expect from faulty shock absorbers?

You remember that shock absorbers, in combination with other suspension elements, are responsible for damping vibrations of the body and wheels, allowing the wheels to interact reliably and safely with the road, and preventing the creation of uncontrolled car rolls.

The main malfunction of shock absorbers is a change in their operational characteristics, which occurs due to: leakage, wear or mechanical damage to the working parts (rod) of the shock absorber.

What are the consequences of faulty shock absorbers?

impairment of car controllability. Remember the phrase “lost control…”. She surprises, sometimes. How can you not cope with him? The answer is simple: faulty shock absorbers made the car at speed, and when cornering, just a spontaneously moving heap of metal;
increased braking distance, the likelihood of “driving” to the side during moderate or extreme braking;
reduction in vehicle directional stability;
reduction in carrying capacity;
acceleration of wear and failure of suspension elements such as springs, strut supports, wheel bearings, silent blocks, CV joints, etc. That is, the probability of suspension failure accelerates over time;
deterioration in ride comfort in the cabin. Your comfort, by the way, when you feel all the bumps in the road, of which we have no shortage.

How to check the health of the shock absorber

Important! We will talk about how to check the serviceability of the shock absorber, but not its functionality. Performance, that is, compliance of the shock absorber with the manufacturer’s technical specifications, is a separate matter.

You can check the serviceability of the shock absorber on your own only by visual inspection. By visual inspection without dismantling the shock absorber, you can determine the serviceability of the seal and the presence of mechanical damage (dents).

Namely, if there are oil smudges and drops on the shock absorber body, immediately draw the conclusion that the seals have become unusable. This indicates an imminent failure and the need to replace the shock absorber.

The existing version that the presence of oil “fog” on the body is a malfunction is somewhat erroneous. This deposit during shock absorber operation is considered normal.

If you are diagnosing a shock absorber after removing it, then you should pay attention to the rod: there should be no traces of corrosion, scuffing and, especially, deformation of the rod.

How to check the performance of a shock absorber

That is, how to check whether the characteristics embedded in this mechanism meet the requirements for the shock absorber to perform its direct functions. This type of shock absorber diagnostics can only be carried out using instruments or on special stands.

Device with displacement sensor . The device is “manual”. It is attached to the fender of the car, and the sensor is placed on the ground. Data is collected using the body rocking method. At the same time, factory parameters are entered into the device, which correspond to the standard performance of the shock absorber. The performance of the shock absorber is determined as a percentage.
Shock-test (shock test) is carried out on a stand. The axle wheels are raised and lowered sharply. The computer records the vibration damping coefficient of the shock absorber.
Express diagnostics (sharp braking). It is held at a stand with platforms. At the same time, the effectiveness of the braking system is diagnosed. The car drives onto the platform and brakes sharply. Body vibrations and load on the platform sensors are recorded. The accuracy of this method leaves much to be desired.
In addition, there are stands for testing the performance of shock absorbers using the amplitude-resonance method.

Each of the listed methods shows the efficiency coefficient of shock absorbers, on the basis of which you can make a decision about the performance of the shock absorber and the need for its repair or replacement.

How to check new shock absorbers

It would seem that it is simpler. You come to the store, they give you a new shock absorber in the package (a pair, since a prerequisite for replacing a shock absorber is replacing a pair on one axis).

Easier, but not very simple. Many manufacturers have learned to make beautiful packaging, but do not burden themselves with instructions describing the technical characteristics of shock absorbers.

You can check a new shock absorber on a stand, but... only after purchase. Therefore, the old antiquated method of checking a new shock absorber remains.

Visual, external inspection . We check the markings. Which must correspond to the manufacturer's catalog. We check the shock absorber for mechanical damage to the body, rod, seals, etc. check the threaded connections. Naturally, we should not talk about any oil leaks.
Geometric Compliance Check . You will need a ruler and a caliper. We check the length in the shifted state, the stroke of the rod (we focus either on the manufacturer’s recommendations, or the deviation from the nominal values can be within ±5 mm). Rod diameter.
Checking the performance of the shock absorber. Single-pipe can be checked without prior preparation. Compress and stretch the shock absorber 3-5 times. The movement of the rod should be smooth, with the same force, without jamming or sudden jolts. There should be no extraneous noise or squeaks other than natural “sniffing”. This is the result of fluid flowing inside the shock absorber. The two-pipe one must be pre-prepared, namely: pump it 3-5 times, then place it vertically, the stem up, and after that do not put it down or turn it over.

Good luck with diagnosing the serviceability and performance of shock absorbers.

Buying tips: how to check shock absorbers

Reliability corrupts. Owners of modern cars are not too worried about the condition of those components that are not visible, those that are buried somewhere deep and do not remind of themselves in any way. They just may not remind you at the most opportune moment. This is why diagnostics exist: like it or not, you need to check certain components for serviceability.

In the photo, oil shock absorbers are the most comfortable type of shock absorbers

Signs of a dying shock absorber

Shock absorbers are just such components. As long as they do their job properly, you don’t think about them. Modern shock absorbers are very reliable, but, like any mechanics, they have their expiration date. We won’t mumble lectures about what needs to be checked, diagnosed, and serviced in a timely manner. Instead, let's look at the signs that your shock absorbers will soon need attention. This can manifest itself in different ways:

The car nods when braking actively.
Strong sway during sudden maneuvers.
Noticeable increase in braking distance.
Increased driver fatigue during long runs.

The last point is not at all as harmless as it might seem. Physiologically, a person is tuned to a certain vibration and a certain amplitude when moving. Either on foot, or on horseback - whatever. If the vibrations are less than when walking, we get motion sick, if more, they shake us and lead to physical discomfort. Therefore, when driving on tired shock absorbers, we also get tired much faster.

Video tips for checking shock absorbers

Operating principle and types of shock absorbers

Before checking the shock absorbers, it would be logical to remember what exactly we are checking. At the same time, let’s remember what types of shock absorbers there are and how they are designed. The most versatile shock absorber is a spring. It combines the ability to spring the body and also prevents it from swinging. It has already outlived its usefulness, and today we are offered shock absorbers of only three types:

Oil shock absorbers. The twin-pipe hydraulic shock absorber is the most comfortable and soft. His lifespan is short and he has one bad habit. Under heavy loads and high speeds, oil boils, losing its properties. The only thing that can attract them is their low price.
Gas-oil. A little stiffer than hydraulic ones, but in terms of characteristics they are most applicable to our roads. The two-pipe design made it possible to place nitrogen under a pressure of 3 atm in the compensation volume, which cools and prevents the oil from boiling.
Gas shock absorbers. The toughest and most expensive. They are arranged according to a single-pipe design and are filled with gas under high pressure, usually up to 25-30 atm. Gas shock absorbers hold the road well, but are not always suitable for everyday use.

Gas-oil shock absorbers are most applicable to our roads

Although it would be more logical to divide shock absorbers into single-tube and double-tube, since they differ significantly in design. A twin-tube shock absorber consists of a master cylinder filled with oil, inside which a piston runs. This cylinder is placed inside the second, reserve cylinder. In monotube shock absorbers, oil and gas are located in one cylinder, and they are separated by a floating piston.

Checking shock absorbers for functionality

If a shock absorber is installed on a car, then there are several ways to check its performance . Each of them is quite simple, however, even in the early stages it will allow you to identify the malfunction:

Visual inspection. Without a visual assessment of the condition of the shock absorber, it will not be possible to immediately identify at least obvious signs of its malfunction. The first thing that catches your eye is the oil marks on the body. Oil may get in accidentally, so you should wipe the shock absorber, drive it for a few days and repeat the inspection. There should be no traces of rust on the rods, they should look perfectly smooth and shiny.
In addition, you can inspect the tires for uniform wear, but this may not always lead to the trace of the shock absorber. An unbalanced wheel also wears unevenly. That's all we can figure out visually.

Gas shock absorbers are considered the most expensive and rigid.

You can check the performance not only on a car, but also on a separate shock absorber, but such stands are very rare, and not everyone wants to remove the unit for testing. Unfortunately, upon purchase, we cannot check the shock absorber in any way except by carefully studying the packaging and inspecting the part itself for external damage, dents and scratches. In this case, the warranty card is the key to a successful purchase.

There is no point in saving on shock absorbers. With proper operation, factory components can last up to 50-70 thousand mileage, and a good shock absorber is the stability of the car and your safety.

How to check shock absorbers for performance yourself: simple methods

Hello! Operating a car involves the need to constantly monitor and control its behavior, as well as the condition of the vehicle components. One of the key ones is the suspension. In this regard, I want to tell you how to check shock absorbers without outside help.

There is nothing complicated in carrying out diagnostic measures. And you can see this for yourself after reading the material. If the rear or front struts begin to wear out, or there are problems with the shock absorption system in the car, a check will let you know about this.

I advise you to do this while operating your car, as well as when buying a used car. By looking at the suspension you can understand the general condition of the car. If the car is new, there will definitely be no complaints about the suspension and shock absorber.

In total, we will consider 5 methods with you. 4 of them are performed independently. Another professional one, and involves testing on a bench.

Verification methods

While operating your car, you may have some doubts about whether the current shock absorbers are suitable or not. They come in front and rear on cars.

Regardless of where and what elements are on your car, the testing methods to identify problems are identical for all. I will only add that the shock absorber can be oil, gas or gas-oil. If you want to know which one is better, write in the comments. We will prepare a separate material on this topic, where we will discuss the strengths and weaknesses of each design option for a car shock absorber.

The main advantage of the methods is that the test can be carried out without removing them. These are express tests of performance and current condition.

Yes, removing the shock absorber will give you a better understanding of what's going on with it. After all, problems with the suspension do not always mean that the shock absorber is faulty.

All procedures presented are applicable to any vehicle:

for VAZ 2107;
VAZ 2110;
on Gazelle;
Lade Priora;
Hyundai Accent;
Daewoo Lanos;
Renault Logan;
Prado 120;
Nissan Almera;
Kia Sportage;
Chevrolet Aveo, etc.

All ways to independently determine the malfunction of the shock absorber support or the shock absorber itself are divided into the following types:

visual;
rocking method;
behavior;
heat;
bench test.

Now I propose to talk about each of them separately in order to clarify some of the nuances.

Visual method

For a visual inspection, you will need to carefully examine with your own eyes the condition of each of the shock absorbers installed on the machine. Here it is better to use a pit or overpass, and also take with you a portable source of good light.

There are several indirect signs indicating that the shock absorber is not working or its life is at its limit.

If the machine has not been used for a long time, traces of corrosion appear on the surfaces of the shock absorbers;
Most often, rust is noticed on visible areas of the stem;
If there is rust, there is a high probability of oil seal wear;
If there are traces of oil on the body, this is also a bad signal;
This sign indicates depressurization;
When an oil leak occurs, repairs sometimes help, but often the problem is eliminated by replacement;
If you find traces of oil, wipe these areas with a dry cloth, and after a few days, look at these areas again;
If oil reappears, they should be removed and replaced.

A leak of working fluid indicates that the integrity of the housing has been compromised. It's not worth using the car, but you can still use it for a while.

But the absence of corrosion and oil during a visual inspection does not guarantee that everything is fine with the shock absorber. There is still a possibility of wear and tear on the internal components of the structure.

Another method that allows you to diagnose a shock absorber malfunction. Often appears in various thematic videos. Quite easy to use and at the same time informative.

To check, you need to stand near the front or back of the car, depending on what elements you are checking, put two hands on the hood or trunk, and begin to actively swing up and down, pressing your hands to the body. It is better to do this near the wheel. When the swing is over, with a working shock absorber, the car should return to its original position without additional vibrations. If you let go of the car, but it continues to rock, this is a bad sign.

A functioning shock absorber allows vibrations to die out after just 1 or 2 swings without your participation. If the body shoots up sharply, this indicates a malfunction of the strut. And when you can’t rock the car at all, the problem is a jammed rod.

The method is not always effective, since some cars are difficult to physically rock. Plus, this technique diagnoses problems only with really worn shock absorbers.

Machine behavior

The next test option, in my opinion, is the best. Although the signs will still be indirect. If you notice at least one of the symptoms listed below, this is a reason to contact a car service for diagnosis.

When entering the road, the car begins to actively jump over uneven surfaces, which has not been observed before. Behavior is no longer so gentle;
The car can also sway violently in different directions. When hitting a bump, the vibrations do not stop for a long time. This is especially noticeable for rear seat passengers;
The car's response to steering has changed. It is not as clear and sensitive;
The sound of a faulty suspension element appeared in the form of rattling or knocking. Especially when driving on uneven areas.

Just don’t think that the check needs to be carried out at high speed or when skidding. An average speed and an ordinary flat road are enough, on which you should perform several maneuvers such as a snake. Try to accelerate and stop.

Any of these signs indicates that there is a problem with the suspension. This is not necessarily the shock absorber. But this is an obvious reason to do a more thorough check. And it’s better to get diagnostics done at a good service center.

This is the least popular verification method among motorists. Although it has good accuracy rates.

It consists of checking the shock absorbers according to their degree of heating. The downside is that you have to work very quickly until the signs disappear due to natural reasons.

The point is this. You need to drive the car, then park on a pit or overpass, get to the shock absorbers and feel them with your hands. The thing is that during operation the shock absorbers heat up, generating a large amount of thermal energy. Feel all the elements. If one of them is cold or warm, although all the others are hot, the shock absorber has lost its functionality. It needs replacement or repair.

Bench diagnostics

If you want to get professional advice and a more accurate answer, you can contact a car service center where there is a special stand. The method is fast, not very expensive and informative if carried out correctly.

But he is not as good as some people think. Different stands are based on different diagnostic parameters. If there are problems with the design other than shock absorbers, the results may not be correct.

Also, different stands use certain algorithms when assessing the effectiveness of the suspension. That is, different services may give you a completely different final diagnosis. And if the craftsmen are unscrupulous, they will tell you that the shock absorbers have come to an end and need to be urgently replaced. Although in fact they can last quite a long time.

I can say one thing. It is absolutely forbidden to operate a car with faulty shock absorbers. This entails a number of very dangerous and undesirable consequences.

If you need a more accurate independent assessment of their condition, I recommend using a combination of several verification methods in turn.

Thank you to everyone who reads us! Leave your comments, ask questions and suggest new topics for discussion!

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Which shock absorbers to choose and how to check

Every motorist knows that shock absorbers are exactly the part of the car that requires mandatory replacement in case of wear. The service life of shock absorbers depends on factors such as:

Quality of the part
Condition of the road
How to drive the car

Nuances of choosing shock absorbers

Shock absorbers on the market are divided into oil and gas-oil. The peculiarity of oil shock absorbers is that the working element in them is oil. Gas-oil shock absorbers are distinguished by the fact that they are additionally pumped with gas under pressure. The design of both oil and gas-oil shock absorbers is actually not as important as their characteristics and consumer properties.

It should be noted that the cost of gas-oil shock absorbers is higher than the cost of just oil shock absorbers. The price difference can sometimes reach 30%. In this regard, the question arises - is it worth overpaying and why are gas-oil shock absorbers better?

According to experts, purchasing gas-oil shock absorbers still makes sense, since they hold the car much better on road surfaces that have small transverse irregularities and bumps. In simple terms, gas-oil shock absorbers help to better press the car’s wheels to the road, as a result of which the car’s behavior even on sharp turns becomes as reliable as possible. All the advantages of gas-oil shock absorbers can be appreciated only during sharp turns at extreme conditions and when moving quickly on a disgusting road surface. Thus, motorists for whom reliable handling is the main thing in a car are recommended to give their preference to gas-oil shock absorbers.

However, there are practically no significant differences in the characteristics of both oil and gas-oil shock absorbers. And drivers who prefer quiet movement to fast driving on a bad road with sharp turns may well opt for oil shock absorbers. Many motorists believe that oil-oil shock absorbers have a shorter service life. But this is not so, such an opinion is erroneous, since currently no official research can confirm this fact.

Shock absorbers must be replaced in PAIRS. Some companies even sell them in packs of two. It is permissible to install one-pipe and two-pipe systems on a car at the same time, but on the same axle they must be identical.

Checking the performance of the shock absorber Preparation

The two-pipe must first be pumped (compressed 3-5 times and stretched to full stroke), placed vertically with the rod up (deviation from the vertical is no more than 30°), and then not placed or turned over.

The monopipe can be checked in any position without preparation.

Fully compress and extend the shock absorber 4-6 times, before each cycle rotating the rod in the reservoir approximately 120° around its axis.

Movements should be smooth, with noticeable effort, without jamming throughout the entire stroke length. Knocks, squeaks and other noises are unacceptable, with the exception of “sniffling” - this is caused by the flow of liquid through the valve system.

The shock absorber resistance during compression is usually less than during rebound (about three times). At the end of the stretching stroke there should be no decrease in force (failure), and compression there should be no increase (support). In a pumped two-pipe, failure indicates a lack of fluid, and backwater indicates its excess. In a single-pipe, failure is a sign of a damaged floating piston seal.

Liquid should not leak from the shock absorber. Traces of its film on the rod are acceptable (it will be greasy to the touch), but without ring-shaped deposits on it and at the oil seal, which reappear after they are removed with a cloth.

How to diagnose car shock absorbers?

To determine the technical condition of the car, you need to diagnose the vehicle. This operation is included in the repair and maintenance of the machine. Among other actions, it is important to check the chassis and shock absorber strut - are there any problems with these components? Otherwise, when the machine moves, other components and assemblies will be subject to increased wear, since the shock absorbers will not dampen the impulses that arise during movement. In addition, this will cause discomfort to the driver and passengers and will also affect the driving performance of the car.

In order for the diagnosis to be objective, you need to know exactly how to check automobile shock absorber struts for performance.

How to check shock absorber struts?

Many inexperienced motorists do not know how to check the struts for faults. There are several ways to check shock absorbers:

Visual inspection

The operation can be performed without removing the wheels.
It is important to consider that the front and rear struts are located next to the springs. In some cases, they come with them. There should be no oily smudges or traces of them on the flasks. These signs indicate that the rack is broken. You also need to inspect the rods. This operation is performed when driving the car onto a lift. The part must have no signs of corrosion or damage. The disadvantage of the method is that the test results will not be able to provide objective information on the condition of the suspension elements. The thing is that the racks may have internal defects that cannot be seen during a visual inspection, and as a result, the diagnosis will be incomplete. Important! If the cover is worn unevenly, this indicates a malfunction of the racks.

Checking damping properties

To implement this, you will need to rock the car. It is important that more than 1-2 presses on the wing of the car are not allowed. The method allows you to identify a completely failed suspension element. The important thing is that such a test will not allow you to evaluate the performance of the components if the rod is jammed. Then, as a rule, the buildup will not be successful.

Diagnostics while driving a car

Constant skidding, an acute reaction to even the slightest bumps or bumps, an increase in braking distance - as a rule, all this indicates problems with the suspension, including shock absorber struts. These problems put traffic safety at risk; such a suspension cannot be used.

Diagnostics by removing parts

The dismantled suspension element is installed vertically, relative to the ground. Next, you need to grab the upper rod and pull it out, then push it down. The working component will have strong resistance. If the rod moves freely, it means that the working fluid has run out or air has entered the mechanism. This check makes it clear that you should purchase a new set of racks.

Diagnostics on a vibration stand

One of the most reliable ways to detect suspension failure. The bottom line is that the device simulates the movement of a car on the road, thereby checking the racks and other mechanisms of the vehicle.

Before carrying out diagnostic work, you should wash the car and perform a number of preparatory measures. The vehicle must be driven to an overpass, inspection hole, or use a jack. Thoroughly wash the wheels and arches from dirt, and use a wire brush to clean these components from corrosion. In addition, diagnostics are performed in a well-lit, spacious room or outdoors, provided that the weather allows the work to be carried out comfortably.

How to diagnose new shock absorbers?

At the moment, in the automotive spare parts market, along with original parts, you can find a huge amount of counterfeit goods. The use of counterfeit components leads to rapid vehicle breakdown and also endangers the life and health of the driver and passengers. Therefore, when purchasing, you need to know how to check shock absorbers:

Inspect the part, look for oil stains, defects, and contamination. If there are any, then you should refuse to purchase.
Check the markings with those indicated in the manufacturer's catalogue. If they do not meet the standard, it means that a fake part is being sold, the quality of which remains in question.
When purchasing gas shock absorbers, you need to bleed the rod. About five times. There should be no “sticking”, the movement of the part on a working shock absorber is smooth, the rod does not make unnecessary sounds.
The stroke length of the rod should not deviate by more than 5 millimeters from the value declared by the manufacturer.

Important! Checking shock absorbers when purchasing is a mandatory operation, otherwise there is a high risk of purchasing a counterfeit product.

After completing the diagnostic operations, provided that no defects are identified, you can safely purchase the product. As a rule, such shock absorbers will last a long time.

How to check shock absorber struts yourself?

Every driver should know how to check the shock absorbers on a car. Do-it-yourself operations are performed using the following methods:

Visual inspection of the element

Using this method, you can find out about the main faults of the racks. If they are broken, then the suspension is unsuitable for further use. Malfunctions are indicated by drips, uneven tread wear, and rust on the rods.

Car rocking

When swinging, there should be resistance. If, when pressed, the car flexes easily and also accumulates easily, then there are problems with the suspension.

Dismantling the part

Allows you to perform certain actions with the shock absorber rod and strut. Defective elements checked in this way are usually subject to replacement.

Important! If you do not have confidence in your own abilities, then you should refuse to replace it yourself. After all, in case of failure, the situation can worsen.

How are shock absorber struts diagnosed on a bench?

Diagnostics of shock absorbers on a stand is carried out in specialized service centers, the average cost of performing this work is one thousand rubles.

So, how do you test shock absorbers on a vibration stand?
To do this, you will need to drive the car to a special platform, which begins to vibrate, thereby simulating road conditions. During this work, the racks, components and assemblies of the vehicle are checked. If problems are identified, the motorist will have to purchase new struts.

Important! It is recommended to carry out a complete diagnosis of the vehicle every 30-50 thousand kilometers, depending on the intensity of use of the vehicle.

Consequences of shock absorbers failure

So, what problems does a motorist face when the suspension breaks down? As a rule, the list of consequences of shock absorber failure is as follows:

Increased braking distance of the car, deterioration in handling, increased tire wear.
Failure of bearings in the chassis of the car.
Operation of faulty struts leads to destruction of the car body.
An increase in the likelihood of an accident on the road, and as a result, a decrease in the safety of drivers and passengers.

Important! When purchasing new racks, you need to select the type of part that was previously used. As a rule, this will not cause problems when using the car, as a result of changes in the driving characteristics of the vehicle, and, as a result, the comfort and safety of the driver and passengers will remain at a consistently high level.

After all diagnostic work has been carried out, they begin to replace the damaged shock absorbers with new ones. You can learn how to properly dismantle old ones and install new struts from the car's operating instructions.

To summarize, it is worth saying that suspension problems, as a rule, affect the operating conditions and comfort of using the car. As a result, they also pose a threat to the safety of the driver and passengers. The causes of failure can be many factors, but, as a rule, the main one is the failure of the shock absorber struts. To eliminate the breakdown, you will need to carry out a high-quality diagnosis of these components; you can learn how to do this from the above material.