Quite often you can hear the question: how to change shock absorbers, because there are many people who want to repair the suspension themselves, both among experienced car owners and among novice motorists. But contrary to popular belief, it is not difficult and not difficult. The answer to the question will vary slightly depending on the car model and whether the shock absorbers are front or rear. But if you replaced the front strut of the car with your own hands, then you will not have any questions when replacing the rear one.
Tool kit for replacing shock absorbers
For DIY repairs you must have:
Wrenches included. It has a special design designed to facilitate the work process in a small, confined work space.
The tool consists of a handle as a single unit and a working part, which has a special design. Keys included:
- Carobaceae. Used for screwing fasteners that have a hexagonal shape;
- Caps. Work with cap devices;
- Combined. On one side there is an open-end wrench, and on the other a spanner;
- End A type of wrench used to turn a fastener;
- Adjustable. A universal tool that has adjustments;
- Balloon. Unscrews car wheel mounts.
- Jack. A special mechanism for lifting loads of various volumes, without auxiliary devices;
- Screwdriver Set. For ease of use, some types are produced with a magnetized tip. Handles can be of various modifications;
- A puller is a specialized device that allows you to compress shock absorber springs for repair work;
- Stoppers. An auxiliary tool that supports a car on a jack.
Types of car shock absorber struts.
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The purpose of a car's shock absorber strut is no secret to most drivers. It consists in damping vibrations that inevitably occur in the coils of springs while overcoming all kinds of road irregularities. Today we will talk about the existing types of shock absorbers, talk about the principles of their design, and also highlight the advantages and disadvantages.
Twin-tube shock absorbers.
This type of shock absorber struts has the largest presence on the market. Their operation is based on two cylinders filled with a special hydraulic fluid or gas. During compression work, it (he) flows from a smaller cylinder to a larger one, compressing the air contained there in some quantity.
In the event of a rebound, the bottom valve goes into opening mode, which allows the liquid (gas) to freely return to the space of the inner flask. The main requirement for hydraulic fluid or gas is an increased level of viscosity and a high level of compression resistance.
— The disadvantages of these shock absorbers are their susceptibility to heating as a result of friction that occurs when liquid flows, excessive air saturation (aeration), and the impossibility of installation in the lower position of the rod.
Monotube shock absorber struts.
The design of monotube shock absorbers has some differences from the previous type. They are complemented by a pair of built-in valves, and the hydraulic mixture is separated by a special piston into gas and liquid compositions. The use of such racks makes it possible to use them on vehicles with any options for the location of the rod, directed both up and down.
The single-pipe system allows the use of a larger chamber volume. The stand cools perfectly. In general, the car feels noticeably more confident on the road, clearly maintaining its trajectory and reducing any roll to a minimum.
Unfortunately, monotube shock absorbers are not without their disadvantages. Among them, we highlight the susceptibility to mechanical damage (despite the fact that the presence of even a small dent on the body will force you to replace the strut, you can find out how to do this here) and excessive heat exchange with the “outside world”, as a result of which the shock absorber works noticeably softer in winter than in winter. summer heat time.
Hydraulic shock absorbers.
Hydraulic shock absorbers consist of a working cylinder filled with liquid hydraulics, through which a piston and rod move, controlled by a clearly calibrated set of valves (bypass, rebound valve and compression valve).
The main feature of using hydraulic struts is the ability to individually configure their operating parameters. They can take into account any operating factors from driving mode to vehicle driving style. For example, closed valves direct all fluid flow into the bypass channel, while making the rack as rigid as possible. Opening the compensation chamber valve allows for a certain amount of "flexibility".
Gas-hydraulic shock absorbers.
The design of shock absorbers of this type is extremely similar to the previous type. The main difference is only in the use of gas, along with hydraulic fluid, filling the lower part of the cylindrical body. Basically, various variations of inert gases or nitrogen are used for these purposes. The smaller the diameter of the rack, the higher the gas pressure inside it and vice versa. The gas composition is stable. It is held at the bottom of the shock absorber by a collar and spacers.
The main disadvantage of gas-hydraulics is its high cost. Basically, such shock absorbers are intended for top-level cars, which have the ability to automatically adjust the suspension operating modes.
Results.
To conclude the article, let’s say that shock absorbers of the first three types are in greatest demand. The main reason is ease of installation and relative low cost. Considering the important role of shock absorber struts, we urge you to closely monitor the quality of their work and, if necessary, replace them in a timely manner.
Replacing shock absorbers (step by step instructions)
The top part of the shock absorber is installed to the body, the bottom part is installed to the suspension. This fastening method simplifies future replacement. Replacing front suspensions is much more difficult.
With the expansion of automotive production of front-wheel drive vehicles, difficulties arise in replacing the suspension.
There are two replacement methods
Monroe
An American brand, produced in Belgium, which can be found not only on cars of the northern continent, but also on European ones. This company is a leader in sales of shock absorbers as spare parts.
The reliability of the racks is 20 thousand km, which is 2 times less than in the same KONI. This is a normal economy option for middle-class road cars designed for smooth asphalt. But in harsh conditions their effectiveness is significantly reduced.
The Reflex series is considered one of the best, with an improved suspension that ensures a comfortable ride. There are also Original shock absorbers that are as close as possible to the factory ones; Radial-matic and Gas-Matic, with pure two-pipe hydraulics; and Van-Magnum for SUVs.
The first method of replacing shock absorbers
The complexity of the work is easier. Its use is not often used. Installing the shock absorber through the U-shaped bracket, through the drive shaft.
The replacement technology consists of:
- We dismantle the wheel;
- Remove the plugs under the hood of the car. Slightly loosen the nut that holds the shock absorber rod. Do not twist it completely. The spring may jump to the side, which is not safe for your health;
- Do not completely unscrew the fastening nuts of the upper support;
- Using a puller, remove the tip;
- We mark with a marker the location of the upper adjustment bolt, which adjusts the wheel alignment angles;
- Unscrew the mounting nuts of the shock absorber strut. We knock out the fastening bolts themselves with a hammer or sledgehammer;
- Pull the hub down;
- Under the hood there are three mounting nuts that need to be unscrewed;
- Release the rack;
- We hold the shock-absorbing spring with ties;
- Unscrew the shock absorber rod;
- Carefully remove the support and the bowl with the spring. Let's take it out. The shock absorber is located in the strut housing.
- After going through the removal process, the shock absorber has become unusable. We install the new part in the reverse order. Starting with the bump stop.
The main thing is that after replacing with new ones, it is necessary to bleed the shock absorbers. Sometimes a shock absorber may be called a cartridge. In some cars, you can replace the cartridge.
When replacing which, we disassemble the rack further. We proceed further according to the scheme.
- Using a hammer and chisel, knock out the support washer from the car body;
- Under the washer you can see the fixing nut; it needs to be unscrewed. Now you can see the cartridge that needs to be replaced;
- We replace it with a new cartridge.
- We screw it on. We make a fixation;
- We place all previously removed parts on the rack;
- We install the replaced rack on the car.
Strict control of the tightening of bolt connections is necessary. On the opposite side of the car we perform work similar to what was done.
How to restore gas pressure inside the strut (Repair of gas-oil shock absorbers)
- Securely clamp the shock absorber vertically into the yew. Clean the shock absorber thoroughly and blow out the rod inlet hole. Next, disconnect the protective cap of the rod.
- Connect the gas blower to the rod. We pump up the gas to the required rate. Be especially careful during this procedure. You will have to pump more than once until you achieve the desired adjustment effect.
- Lubricate the stem seal and replace the protective cap.
Car owners often argue about what to pump into the shock absorber: compressed air, nitrogen or carbon dioxide. If you are carrying out repairs on your own, in the garage, then there will not be many options. In our case, compressed air will not spoil the condition of the shock absorbers, because this is already a repair, and not the initial production of the strut at the factory.
The second method of replacing shock absorbers
This method is more labor intensive. Back in the thirties, an interesting design was developed for the Chevrolet Cadet, where the shock absorber and spring were placed in one strut, which on one side had a hinge installation.
With the help of which the stand rotates. Provided that any angle of inclination is determined. This design of shock absorbers allows you to reduce the cost by completely removing the upper arm.
Fastening is done directly to the shock absorber strut. The design was named after mechanical engineer Earl McPherson.
Workflow diagram:
- Using a jack, remove the wheel from the front, first turning the hub drive shaft nut;
- We release the shock absorber rod by unscrewing the brake caliper. The rubber pipeline must be in a free, non-tensioned state; the brake pads can be inspected immediately;
- Release the tie rod end;
- Unscrew the ball joint and release the front drive lock;
- Carefully, pulling towards you, pull out the hub;
- By unscrewing the upper support, we remove the stand itself;
- We replace the worn cartridge with a new one;
- By analogy, we assemble everything in reverse order. Using the same algorithm;
Necessarily. After going through the process of replacing the shock absorber, it is necessary to perform wheel alignment adjustments.
The MacPherson suspension design is the same on different car models; they may differ in manufacturing design. Replacing front shock absorbers differs in some details. The shock absorber can only be replaced together with the body.
Some car models do not have an adjustment bolt. These car models use a bolted connection. The replacement process is complicated by removing the hub. To do this, you need to loosen the lugs by driving a chisel between the lugs. We release the hub. The replacement algorithm does not change further.
Due to the heavy load, the elements of the front shock absorbers become unusable and require replacement. If you decide to make the replacement yourself, with your own hands. Feel free to get down to business.
What equipment is needed for repairs?
Before replacing it yourself, you need to carefully read the video, which shows the main points of installation. The list of required tools and materials includes the following:
- jack or lift;
- a set of heads – it is desirable to have knobs and extensions;
- open-end and ring wrenches;
- screwdrivers: slotted and Phillips (different sizes);
- iron brush;
- hammer (metal, rubber);
- pliers;
- spring ties.
Another must-have product for working with old shock absorbers is WD-40. If it is missing, it will be impossible to disassemble the threaded connections. Especially if the car has traveled 50 thousand km or more.
There are many ways to check the performance of a shock absorber. The simplest and most accessible to everyone without exception is the visual method. The presence of oil leaks and other defects are the first signals that a part needs to be replaced. The replacement process includes many steps. Car repairs must be approached responsibly. This will avoid many difficulties and difficulties.
Timely replacement of struts will save the car owner from expensive subsequent repairs. Since if the suspension malfunctions, all components that include rubber wear out without exception. These are anthers, ball joints and many others.
