How to seal a car's expansion tank: rules at home

A car's expansion tank is an integral component of the cooling system. Its task is to compensate for the increasing volume of antifreeze or antifreeze at high temperatures and increased pressure in the cooling system. The design features of the cooling system dictate what shape the expansion tank has and what additional functions, in addition to collecting liquid, it has.

Why does antifreeze come through the lid?

If the engine overheats or the expansion tank swells, many inexperienced drivers immediately run to open the lid and are very surprised, and many are frightened, by the antifreeze leaking out under pressure.
We will immediately reassure you - this is normal. The fact is that when the serviceable reservoir cap is closed, a pressure equal to 1.5-2.0 atmospheres is created in the cooling system. Moreover, we all know from physics that the boiling point of any liquid is directly proportional to the surrounding pressure. That is, the higher the pressure, the higher the boiling point.

Therefore, pressure above atmospheric pressure in the cooling system is created specifically so that antifreeze boils not at 100C (1 atm.), but at 115C (1.5 atm.) and 120C (2 atm.).

After the engine is turned off and the lid is opened, the pressure equalization process occurs, the liquid flows from more to less, while it continues to expand, since the engine continues to gain temperature for some time, i.e. the point at which it begins to cool has not yet been passed.

If the antifreeze boils, it means the engine has overheated. In this situation, you do not need to open the lid right away, since the coolant may splash out on your hands and face under pressure - a burn is inevitable. Just in such a situation, when the tank cap is not working, the latter can swell.

Expansion tank VAZ 2114: main breakdowns

It would seem, what kind of damage can happen in a piece of plastic? But yes, they exist:

Cracks appear on the body, from which liquid leaks.
Violation of the integrity of the plug that regulates the pressure in the system.
Destruction of the thread on the neck and other damage.

As for the plug, everything is banal - the valves are clogged and excessive pressure is not released. Associated symptoms - the tank swells and becomes like a ball.

The worst thing that can happen is the fluid bubbling in the tank. This is a clear sign that there is a breakdown in the cylinder head gasket. But this is a separate story, which will be discussed in one of the following articles. Sometimes air pockets appear in the system. In this case, the stove does not work well, therefore, heat exchange does not occur correctly. It’s easy to get rid of air pockets - install the cap on the tank and warm up the engine to operating temperature. To be sure, crimp the long pipes with your hands.

Selecting repair methods and adhesives

Radiators in trucks and cars are an important part that helps cool the mechanism and remove excess heat from the engine. Cool liquid circulates inside the device through pipes and hoses, and the convenient location of the upper part under the hood allows it to be blown with air.

Most cars are equipped with aluminum radiators. This material is ideal for this purpose - it is light, durable, not subject to corrosion, its thermal conductivity is high (it gives off heat and the parts will not overheat). Aluminum and plastic cooling batteries have replaced products made of brass and copper, which are much more expensive. But due to the chemical features, such tanks are much more difficult to repair, although nothing is impossible. The radiator can crack even from a small impact, and if it is made of plastic, even a large defect may appear.

The easiest way is to seal the crack with a suitable adhesive. But choosing glue is not easy - most compounds do not stick, others quickly peel off. This occurs due to regular changes in temperature and pressure in the cooling system.

How to seal a radiator, and what other method can be used at home? Here are the main ones:

Soldering. Heat-resistant plastic, from which radiators are made, as well as aluminum parts, can be held together using a regular soldering iron.
Repair by cold welding. The method is based on the use of special adhesives that melt the edges of the material and tightly seal the crack with a heat-resistant seam. Suitable if the radiator is plastic.
Using adhesive sealant. Only very small cracks in plastic radiators can be sealed. Like other measures, this one is temporary.

An effective remedy for eliminating leaks is 3M DP8005 two-component adhesive adhesive. The composition contains acrylic, which can glue even the most complex types of plastic, for example, polypropylene. If the radiator bursts, this material will be ideal. The seam it creates is not destroyed by moisture, aggressive chemicals, or temperature changes. But the price of such a product is very high (up to 1,500 rubles), so you need to think about the feasibility of purchasing it compared to replacing the radiator.

Another glue is Hosch plastic welding glue. If the radiator is plastic, you can buy the product without hesitation. Pressure up to 12 atmospheres is not a problem for the seam after complete hardening, and any defects can be glued with this glue.

Operating Instructions

For the repair procedure to be successful, it is important to choose the right method and follow a number of recommendations.

Sealing

Before starting the procedure, it is important to prepare everything you need. To do this you will need the following:

soldering iron with a flat tip - its power should be 40 watts;
a fragment of brass mesh with small cells;
metal scissors.

It is permissible to use a more powerful soldering iron. But in this case, you should be careful when working. Otherwise, in the areas where the metal mesh is attached, there is a risk of a through hole appearing in the material.

It is permissible to remove the brass mesh from the car gas pipeline tube. It is located directly in the tank. This mesh is used in the vehicle's power system and plays the role of a filter. After leveling, it can be used as a reinforcing layer. This will help eliminate the tank leak. If you can’t find a brass mesh, you can use a steel one. This material is sold in construction stores and has an affordable price.

After completing the preparatory work and determining the area where the leak is located, the tank should be thoroughly dried. This will help get rid of any remaining moisture.

Soldering is considered the most reliable method for eliminating cracks. Plastic melts easily even at relatively low temperatures. Therefore, to carry out the manipulation it is permissible to use an ordinary soldering iron. To solder the tank, you should perform the following steps:

Place the tank on a flat surface. Moreover, it is recommended to direct the crack upward.
Heat the soldering iron to operating temperature.
Cut the metal mesh so that its length and width are slightly larger than the damaged area. Apply the material to the damaged area.
Using a soldering iron tip, solder the mesh into the plastic. This is recommended to be done along the entire length of the damage.

During the procedure, it is recommended to carefully melt the plastic directly into the crack. Otherwise, it will not be possible to properly deal with the damage. Metal mesh is considered an excellent reinforcing material. However, the patch can only withstand pressure if the plastic layer is uniform.

Sealing

To achieve good results using this method, you must use a two-component composition. To do this, do the following:

Prepare surfaces. It is recommended to clean them from dirt. To do this you should use acetone.
Apply glue. The liquid substance is applied in a thin layer to the damaged area. It is recommended to cover this area with welding granules from another bottle. Then cover the surface again with impregnation glue.
Glue the parts together. The adhesive composition sets almost instantly. Within a few minutes after using the substance, the tank can be returned to its place and filled with liquid.

It is worth considering that the interaction of the liquid adhesive part and the welding granulate causes an exothermic reaction. It is accompanied by the release of steam and heat. Therefore, it is recommended to follow safety precautions.

Welding

Cold welding is considered an auxiliary method that does not provide long-lasting and reliable results. This method helps to achieve temporary fixation, which will ensure comfortable delivery of the vehicle to the service station. For cold welding to produce results, the surface must be cleaned first.

Application of epoxy glue

The use of such a substance is also considered a temporary method. It will not help fix the crack for a long time. To get a good result, the plastic is first cleaned of residual dust, grease, and contaminants.

Hydrogen evolution case

When using aluminum radiators, it happens that water decomposes into hydrogen and oxygen components. This process is caused by the fact that the metal accumulates a static charge, and this is not good. During the production process of batteries, the inside of the device is coated with a protective layer. During operation or due to the negligence of production workers, the layer may be damaged. As a result, the radiator is very quickly destroyed by corrosion.

After two years of use, the radiator becomes unsuitable for further use. You can determine whether hydrogen is present in the system as follows: the constant appearance of plugs, when oxygen has long been displaced from the system and additional water has not been added, indicates that hydrogen is present in the system. You can verify the presence of gases by turning off the air release valves and monitoring using Mayevsky taps. This problem can only be eliminated by replacing the radiators.

Expansion tank in the heating system

Repair of car radiators - we identify breakdowns and fix them ourselves + video » AvtoNovator

An aluminum or copper heat exchanger is the main element of the cooling system of a car engine. Thanks to him, and even an electric fan, it is possible to keep the temperature of the antifreeze within the maximum permissible limits. Owners of used cars over 10 years old often have to deal with unit failure - the long service life takes its toll. But don’t rush to buy a new expensive spare part or go for disassembly. First, find out how you can save money and repair your car radiator yourself.

Why does a leak appear?

The main reasons leading to antifreeze leakage from the cooling system through the heat exchanger are the following:

mechanical destruction of tubes or collector tanks during an accident;
thermal destruction of joints due to overheating and operation without liquid;
corrosion damage.

The first two reasons are somewhat easier to repair because, as a rule, the location of the damage is easy to determine.

In case of corrosion damage, the location of the leak will have to be located. Moreover, it may not be the only one.

What is the danger of a constant coolant leak?

If the cooling radiator is leaking, you need to know what to do or which specialists to contact to fix such a problem. Constant leakage can lead to negative and even dangerous situations:

engine overheating and further failure;
changing the configuration of the cooling system and violating the integrity of the material used as a gasket;
engine jamming, which will entail costly and time-consuming repairs;
thermal burns that can occur when a crack in the radiator ruptures and hot liquid flows out in a fountain.

Why is a radiator needed and why its leaks are dangerous? Now that we have figured out, it’s time to move on to the main issue - considering ways to eliminate leaks and return the cooling system to tightness.

Efficiency and obstacles

There are several technologies that allow you to easily weld parts or products made of brass, but they are not simple, promise significant costs, and require certain work skills from the master. Soldering is an alternative that is technologically simpler, which means this option is also suitable for a home craftsman, since there is no need for a highly qualified performer.

Restoring a plastic radiator

More and more often today there are cars equipped with coolant tanks

https://.com/watch?v=TQZxNiZeTRA

Of course, this is largely practical, since the occurrence of any oxides and destruction by chemical action from the outside is almost completely excluded.

However, the appearance of even a small crack as a result of mechanical stress can lead to active leakage of coolant , a drop in the overall functionality and reliability of the system.

Looking for a leak

If a stain of antifreeze remains under the car after parking, it means there is a leak in the cooling system..

Before removing the cooling radiator or air conditioner, you should make sure that all pipes and the expansion tank housing are in order. The heat exchanger of the interior heating system is also checked.

Before dismantling, you need to drain the liquid from the system . The removed radiator is carefully inspected in good lighting. If the damage cannot be seen, all holes are plugged with tight plugs and the heat exchanger is immersed in water. The emerging chain of bubbles will indicate the location of the leak. If you increase the pressure by connecting one of the pipes to the compressor hose, you can detect a leak faster.

Construction of aluminum radiators

First, let's look at the design of aluminum radiators and what composite materials are used during their production. The first type is a traditional aluminum radiator with plastic tanks ; depending on the model, it may differ in the way the tanks are clamped and the core is made. As a rule, the tanks are clamped with wave rolling or teeth.

Sometimes it may seem that the only difference is in the rolling method, but this is not true. Without going into details, we note that the type of gasket used between the bottom of the radiator and the tank imposes certain restrictions, or, in other words, entails the use of a specific type of rolling. Now let's look at the types of cores.

Source: https://instanko.ru/drugoe/radiator-remont.html

Coolant boiling

If antifreeze (antifreeze) boils, make sure:

Does the radiator fan work and when does it turn on? The sensor may be faulty;
Is the thermostat working? The coolant constantly moves in a small circle, thereby not cooling;
Is the pump working?
Is the cooling system, including the radiator, clogged?
Is the system airy?
Is the valve on the lid working properly? Low pressure in the system can cause premature boiling of the antifreeze.

As for airiness, for example, in VAZ 2110, 2111, 2112, from the experience of their operation, the system practically does not become airborne due to its special design.

In other cars, when replacing the coolant, an air lock may end up in the stove and, over time, make itself felt by overheating the engine and burning out the cylinder head gasket

It is important to monitor the instrument readings

Causes of breakdowns of plastic containers

The car as a whole and its individual elements acquire various defects during operation. The expansion tank is also susceptible to breakdowns, leading to its depressurization with subsequent leakage of coolant as a result of the following reasons:

Increased pressure in the cooling system.
Insufficient thickness of the plastic from which the container is made, leading to cracking of the walls.
Leaving boiling antifreeze in the tank for a long time.
Mechanical impacts, shocks.

If a release of antifreeze occurs, it is necessary to determine the location of the leak and repair the expansion tank.

Reasons for repair

In most passenger cars, the gas tank is located at the rear. The part is shifted to the right side in the lower part of the body. This arrangement is explained by the formation of the correct center of gravity.

The main disadvantage of this engineering solution is mechanical damage to the gas tank. Sharp stones can make a serious hole in the hull and then it will not be possible to do without repairs.

Also, don't forget about corrosion. European cars undergo special treatment, so rust begins to corrode their gas tanks after 7-10 years of operation. But with Chinese cars everything is different. Until recently, the lower part of the body was not processed at all.

The result of the lack of anti-corrosion treatment resulted in a shortened service life. Moreover, not only the gas tank, but also the entire body is susceptible to corrosion. As a result, after five years, most cars need serious repairs, and some simply cannot be restored.

With European and American cars everything is much simpler. Their gas tanks undergo special treatment, so repairs in most cases are needed due to mechanical damage.

Important! To avoid damaging the gas tank while driving, try to drive only on good roads. The crushed stone that often litters country roads can seriously damage your gas tank.

As corrosion occurs, cracks appear in the tank. Moreover, rust corrodes the part not only from the outside, but also from the inside. If this happens, the repair will become several times more complicated.

Important! From the outside the gas tank is exposed to moisture, from the inside there is water, which, although in small quantities, is always present. Despite the fact that European and American gas tanks are much more reliable than Chinese ones, even they require repairs after many years of use

The fact is that it is impossible to completely protect a part from rust.

Despite the fact that European and American gas tanks are much more reliable than Chinese ones, even they require repairs after many years of use. The fact is that it is impossible to completely protect a part from rust.

Luckily, finding out that your gas tank is having problems and needs repairs is fairly easy. There will always be a persistent smell of gasoline or diesel fuel in the cabin. Gasoline will also begin to be consumed faster. In the end, you can just look under the bottom and find a leak.

Why is water flowing from the expansion tank?

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The cork must be German blue!

What do forum users say?

was shorter today at the market and special op in several more stores - the result is that there are no blue caps and there never will be. They unanimously told me that our choice of different modifications ranged from 40 to 50 rubles. I seem to have found a leak - it is poisoning the lower pipe in the connection, tomorrow I will try to put it on the sealant. But how I didn’t understand how to check the plug with a pump can be explained.

Yeah, that’s how it usually turns out - it flows from under the lower thick hose. But sealant, IMHO, is not needed. Just properly treat the necks of the pipes to remove burrs and other irregularities, place them on warm hoses and tighten them tightly with clamps, while paying attention that the clamps lie strictly perpendicular and do not curl into the thickening at the end of the fittings. It would seem like a small thing - but the pressure on the hot antifreeze pushes even through minor irregularities on the fitting when the clamp is placed crookedly.

Purpose of expansion tank

The cooling systems of various cars contain from 5 to 20 or more liters of non-freezing liquid - antifreeze (antifreeze). During operation, the engine, and along with it the antifreeze, heats up from low temperatures in winter to high temperatures in summer.

During engine operation, a pressure of about 1 bar arises in the expansion tank

Since any liquid expands in volume when heated, excess is formed in the cooling circuit of the car, which needs to be directed somewhere. Antifreeze is an incompressible medium, so when it expands, it will create high pressure in the system, which can rupture the pipes and radiator honeycombs. Conversely, when cooled, the liquid will decrease in volume and create a vacuum (vacuum), which acts with the same force.

To ensure normal operation of the power unit cooling system and avoid pressure surges, an expansion tank is integrated into it. Its functions are as follows:

absorb additional volume of antifreeze that expands when heated;
release excess pressure through a plug with a built-in safety valve;
release the fluid back into the system when the engine cools, preventing the formation of air locks.

Large expansion tanks are used on trucks

Additional tips and tricks

In order for the expansion tank repair to be successful, you should follow these recommendations:

It is best to solder the damaged area;
Brass mesh is used as a reinforcing layer - aluminum material will not be suitable in this case;
It is recommended to sand the connecting seam, putty, coat with primer and paint.

The breakdown of the expansion tank is considered an unpleasant violation. To repair damage, it is recommended to use a soldering iron. As a temporary measure, it is permissible to use reliable adhesives. Two-component substances are considered a suitable option.

Gases in the expansion tank

The presence of gases in the expansion tank indicates that the cylinder head gasket has burned out. This is one of the main reasons why it can become bloated.

Burnout of the gasket could occur due to overheating of the engine, unless, of course, the time for its overhaul has arrived, since it is at 150 - 250 thousand km. mileage the service life of this gasket is calculated.

But there is an important point here - the reservoir will not expand if the valve in the roof is working properly, since excess pressure will still be released, but the engine will overheat. But, if the flow of gases is very strong, then the valve will not have time to release the pressure and the tank will eventually swell and even rupture.

In order to detect the presence of gases in the cooling system, you must:

Visually inspect the coolant in the barrel with the engine running and make sure there are bubbles or not. If there are bubbles, then the gasket is most likely broken.
A more accurate method is to use a gas analyzer. The device will accurately indicate the presence of gases.
Use balloons or similar (well, you get the idea). The ball is placed on the neck of the tank and tied tightly with threads. You need to start the engine when it is cold, before the heated coolant begins to expand greatly. If the product inflates quickly, it means that exhaust gases are entering the cooling system, this is only possible through the cylinder head gasket.
Check engine compression. If the car's mileage is not very high, then the compression should be normal, since the cylinder-piston group has not yet worn out. But if the cylinder head gasket is broken, the compression meter will show readings below normal.

You can also check in the area of which cylinder the gasket is broken. To do this, you need to supply air under pressure into the cylinder through the spark plug hole, while the tank cap must be removed.

If the cylinder head gasket is broken, bubbles will be visible in the tanks and air hissing.

The pressure in the cooling system is checked using a 3 atmosphere pressure gauge. To do this, you need to make a tee and connect the device to it.

Start the car and observe the readings. Readings of more than 1.5 atmospheres should already be alarming; 2 – not every barrel can withstand it.

Why does antifreeze leave the expansion tank?

Antifreeze can leave the cooling system only in two ways - leakage and evaporation.

Leaks in the cooling system.

These are the most common cooling system malfunctions. They are diagnosed visually, by wet dirt and drops of antifreeze under the car. It looks visually like this:

Leaking pipes.

It looks like this:

Repair - only replacement! The fact is that rubber pipes are plastic; they change in size and bend during operation. Therefore, adding sealant or mustard will not solve the leak problem, even temporarily.

It has been noticed that pipes for Russian-made cars dry out and crack! If possible, buy from foreign cars and cut to size or switch to silicone! Silicone pipes last longer than the car! But they cost 3-4 times more.

Radiator leaks.

A radiator leak looks like this:

The reason is damage to the cooling radiators from road stones and corrosion! Yes, colleagues, radiators are susceptible to corrosion, especially for aluminum products.

The fact is that antifreeze has a service life of 3 to 5 years, after which the corrosion inhibitors it contains stop working and the antifreeze literally begins to eat aluminum. in order to avoid chemical corrosion, it is necessary to change antifreeze in a timely manner, but we have a separate article about this on our website.

Repairing radiator leaks is possible in two ways - soldering and sealant.

With soldering of radiators, everything is simple: if the tank or neck is damaged and the radiator is copper or brass, then it is soldered with tin using a powerful soldering iron and acid is used as a flux.

A sealed radiator looks like this:

If the radiator is aluminum, or if soldering is not possible, sealants are used.

Here is a short video with an overview of the work of these same sealants:

There is also a popular method - throw 4-5 tablespoons of powdered mustard into the neck of the radiator for every 10 liters of coolant. Mustard works no worse than expensive sealants.

After using sealants, be sure to change all antifreeze after 2-3 days, despite the advertising statements of the manufacturers.

The fact is that ignoring this rule leads to the fact that the sealant, under the influence of oxygen from the air, clogs the radiators.

Pump (pump) leaking.

The water pump or water pump is the only mechanical element in the entire cooling system. The pump is usually driven by a timing belt or a drive belt. Naturally, like any mechanical device, the pump has a certain service life and on most cars the pump is changed along with the timing belt, that is, after a mileage of 50,000-100,000 km.

Naturally, unscheduled pump failures sometimes occur. This manifests itself in the form of play and leakage, here is a short video with an example of a pump failure:

There is only one solution - replacing the pump with a new one; no amount of soldering or sealants will help here.

Cylinder head gasket failure or cylinder head crack.

This is a very common malfunction, especially on older cars and cars that have overheated. On average, a cylinder head gasket lasts 150,000 km or 7-10 years.

If the cylinder head gasket is broken, the coolant will leave the expansion tank very quickly, sometimes gases will be released in the tank and liquid will splash out, and the exhaust will acquire a specific white color. We have a separate article about the signs of a cylinder head gasket failure and we will not repeat it.

Evaporation of water from antifreeze.

There is one important element in the engine cooling system - the expansion tank plug. It is needed to maintain excess pressure in the system.

That is, the cooling system itself is sealed, and the bypass valve operates at a pressure of about 2 kg per centimeter. This was done in order to avoid boiling during local overheating and to prevent the evaporation of water from the antifreeze.

Many car owners, in order to remove leaks, break the valve out of the plug, and for many it does not work due to a malfunction.

After the valve stops functioning, the cooling system begins to operate at atmospheric pressure. Accordingly, on “hot” engines, the antifreeze literally boils, and on conventional engines, with an operating temperature of about 95 degrees, active evaporation of water from the antifreeze occurs.

If you see antifreeze leaving the system, but no leaks are found and the cylinder head gasket is intact, you need to add distilled water to the level and replace the expansion tank cap.

In today's article we looked at all the main reasons why antifreeze leaves the expansion tank. If you want to add to the article, or if you have any questions, write comments.

Seal up a burst washer reservoir on a car step by step

Let's take a closer look at two methods of repairing a burst washer reservoir - glue and glueless (soldering).

Method one - using two-component Hosch glue:

Preparation. Both surfaces to be bonded should be cleaned of dirt using acetone.
Applying glue. The liquid cyanoacrylate component is applied in a thin layer to the crack or hole. Welding granules from the second bottle are added on top and again covered with a small amount of glue for impregnation.
Gluing. The glue sets almost instantly, so within a few minutes after applying the composition, the tank can be returned to its place and filled with windshield washer fluid.

Do not inhale the vapors generated during the reaction process.

VIDEO REVIEW

Method two - soldering:

The surfaces to be joined must be degreased with acetone.
Heat the soldering iron to maximum temperature.
We apply the mesh to the seam so that the edges of the mesh extend to each side by at least 2-3 centimeters.
We gradually heat the metal mesh, fusing it into the plastic.
Smooth out the top layer of polyethylene so that the layer becomes monolithic.
We check the tank for leaks and install it on the car.

When performing work, safety precautions should also be observed. Soldering may only be carried out in a well-ventilated area.

Common Mistakes

Inexperienced craftsmen make the following mistakes when repairing the expansion tank:

choose the wrong method to repair the damage;
do not clean the plastic surface from dirt;
violate the technology of procedures;
do not comply with safety precautions.

Place of the reservoir in the cooling system

A container to compensate for expanding antifreeze can be installed in different places, the location depends on the make of the car. The reservoir is attached to body parts - side members and the interior partition using a rubber clamp or a special bracket. As a rule, the tank is placed on the side where the upper radiator pipe for its connection is located.

Typically the container is installed closer to the radiator pipe

There are containers with 2 and 3 fittings. The latter are connected by three hoses to the following units:

A thick pipe connected to the lower fitting of the vessel connects it to the main line of the cooling circuit - a small circle of liquid circulation that is always open. The antifreeze, which increases in volume, enters the tank through this hose.
A thin tube running from the radiator to the upper fitting. Designed to discharge liquid and steam from the radiator directly.
The second thin pipe, connected to the middle fitting, comes from the interior heater radiator. Its task is the same - to drain excess antifreeze and steam into the container.

Excess antifreeze from three units enters the reservoir with 3 fittings.

The expansion tank is the highest point of the engine cooling system. This is done so that the liquid from the tank can flow into the circuit according to the law of communicating vessels. When the antifreeze level in the container is 3-4 cm above the Min mark on the body, all pipes and units are filled with antifreeze. Including the highest of them - the throttle cooling circuit.

Remaining air from the system is removed through the throttle heating pipes

Diagnosis of housing depressurization

If cracks occur in the tank housing, it is necessary to turn off the engine, wait until the coolant cools down completely, and only then proceed with the following actions:

loosen the fasteners holding the plastic container;
disconnect the pipes and hoses;
dismantle the tank;
drain the coolant;
determine the location of the housing defect.

What is the best way to seal the washer reservoir?

The simplest, most affordable and effective way to eliminate cracks in the windshield washer reservoir is soldering using a soldering iron and a fine metal mesh.

Metal mesh is used as a reinforcing material. It is necessary to eliminate large cracks; if the damage is small, you can do without a mesh.

Metal mesh can be found at the car market; it is sold as a reinforcing base for repairing plastic bumpers in sheets measuring 15x11.5 cm. One such fragment costs about 100-150 rubles.

You can also seal a cracked washer reservoir using special glue.

Suitable for gluing various types of polyethylene and polypropylene, especially strong special adhesive for plastics DP 8005 3M.

This two-part acrylic-based structural adhesive is capable of bonding polymers without prior surface preparation.

The adhesive joint formed by DP 8005 3M glue is resistant to water, high humidity and aggressive solutions, so this composition can be used to repair the windshield washer fluid tank.

The only drawback of this glue is its high price (it costs about 1,300 rubles for a 38-gram package), but if you need to repair the tank of a rare foreign car, then such expenses can be justified.

WEICON Easy-Mix for PE-PP is another effective two-component structural adhesive for bonding polyethylene and polypropylene. This special methyl acrylate based adhesive has high adhesion to low energy polymers (PE, PP and TPE). It glues quickly and, as they say, tightly, but it costs even more (about 3 thousand for 38 grams).
A two-component adhesive-welding solution for polymers from the German company Hosch will help you repair a rare, expensive part.

This glue effectively seals holes and cracks in any plastic products. The adhesive seam remains elastic in cold weather and can withstand pressure up to 12 atmospheres.

In most cases, the joint is often stronger than the plastic being glued together. Hosch adhesive is supplied in a set of two complementary components - liquid cyanoacrylate ether and fine powder granules.

The welding powder contains metal oxides and catalysts that accelerate the setting of the adhesive joint and improve the degree of adhesion. The average cost of a set is 1500 rubles.

Effective means

Today there are many effective compounds on sale that are used to eliminate breakdowns of plastic car parts.

3M DP8005

This product is actively used for fixing different types of polyethylene and polypropylene. This glue is characterized by a high degree of strength. This structural adhesive is a two-component composition. With its help, it is possible to fix polymer compounds without preliminary preparation.

Glue is considered a modern alternative to common methods of mechanical joining or soldering damaged elements. As a result of using the substance, it is possible to obtain a seam that is characterized by resistance to water, high humidity and the action of aggressive substances. Therefore, it can be safely used to repair the expansion tank.

The only disadvantage of the composition is the high cost. However, if it is necessary to repair the tank of an expensive car, such costs are completely justified.

Hosch

To repair plastic car parts, it is permissible to use this two-component welding adhesive. It is produced by a German company. The substance is designed specifically for fixing polymers. With the help of this glue it is possible to seal holes and cracks in various plastic products. The seam remains elastic even in frosty weather. It is capable of withstanding pressure up to 12 atmospheres.

Typically, the connection area with such glue is stronger than plastic. The kit contains 2 components that complement each other. These include liquid cyanoacrylate ether and fine powder. The mixture contains metal oxides. It also includes catalysts that activate the setting of the adhesive joint and increase adhesive characteristics.

Sealing plastic parts of a car radiator

Most plastic repair products are two-component - ready-made compounds do not provide such powerful adhesion to the surface. How to properly seal damage to a radiator? Here is the technique step by step:

Prepare both components for welding the seam on the cooling tank, as well as sandpaper, gloves, cotton swabs, and degreaser (acetone).
Clean the area around the leak from dirt, dust, and grease using acetone.
Mix the glue components as indicated in the instructions. Apply the product to the crack area. Some compounds are applied in a different way. First, you need to sprinkle the plastic with powder, and then cover it with liquid.
If the hole is large, do the procedure in several stages until it is completely tightened.
After 15 minutes, sand the seam until smooth with fine-grain sandpaper.

You can also glue the edges of the crack on the plastic using epoxy glue. The radiator is removed, the area is sanded, and degreased. Epoxy resin is poured over the damaged area and dried for a day. You should not rely on the durability of such a seam - it can last a couple of weeks at most, then you need to purchase a new car part.

How to solder plastic car radiator

Soldering an engine cooling radiator is considered a fairly simple task. However, not everyone can cope with it due to insufficient knowledge of how to solder a car radiator on their own. Most car owners prefer to take their car to a service station.

Surface preparation

Before gluing the plastic on the car radiator, you will need to thoroughly prepare the surface for this process. For this purpose, we will need to clean it from grease, dust and dirt. Lightly dampen a rag and very carefully wipe the areas of plastic around the resulting crack.

In order to achieve a better effect, it is recommended to use an alcohol solution

It is important that in no case should you overdo it. The fact is that too active mechanical impact on the damaged area or excessive pressure on it when cleaning can damage the heat exchanger even more.

Preparing the adhesive mixture

Now you need to worry about how to seal the crack on the car radiator. So, let's prepare the adhesive mixture. If you decide to use exclusively glue specially designed for such purposes, then its use will be as simple as possible.

A small amount of adhesive should be applied directly to the damaged area. When a part is missing a certain piece of the body or there is no gap between the two halves that are formed due to a crack, it is recommended to sprinkle the liquid base with the powder component of the glue.

So, if the crack itself is too deep or a sufficiently large part of the body is missing, gluing must be performed in several stages. You should apply glue to the damaged area two or three times, waiting until each layer is almost completely dry. When the resulting gap can be completely filled with dry gradulant, it is recommended to saturate it with a liquid composition. This way you can be completely confident that it will adhere perfectly to the surface of the spare part.

Cold welding

In addition, you can seal a car radiator using cold welding. Since it comes in the form of a fairly thick putty, it will be enough to apply it to the seam and wait until it cools completely

It is important that this same putty must be applied in a neat and even layer so that the seam is of the highest quality.

Cold welding must be used as:

the main method of restoring performance;
an additional means of securing the result obtained by soldering or gluing.

A layer of cold welding applied on top of the glue layer will allow you to preserve the quality of the auto part repair for a long time and extend the service life of the part.

Final stage

When the glue has completely hardened and all the main working steps have been completed, you need to carry out final surface treatment. It is necessary to ensure that the resulting seam becomes neat and smooth. For such purposes, the soldering area will need to be treated with fine-grained sandpaper, and ideally with a grinding machine.

In this way, you will be able to get rid of all minor defects that will not have the best effect on the further operation of the product. After this treatment has been completed, install the heat exchanger back in its place.

Looking for a leak

Loss of the sealed state of the heating system leads to a loss of pressure. By conducting a complete inspection of the heating device and pipe system, leaks can be detected. Leaks to the naked eye are determined by the accumulation of moisture at joints or holes with a characteristic white coating.

When inspecting, you should pay attention to the connecting elements, couplings at soldering points and direct connections to heating devices. A system with metal pipes may leak at longitudinal seams

Once a leak is discovered, it is worth taking care of its elimination. The joints are repacked, gaskets and gland seals are installed, with a thickness slightly greater than the previous one. If the pipeline is damaged, the damaged section must be replaced.

Leak search

Is it possible to fill a car with gas at home?
As we already understood, if there is no tightness, there will be a sharp loss of pressure. Of course, it is necessary to conduct a full inspection of the system to identify all problems. The main thing here is not to rush!

During the inspection, you need to inspect everything very carefully, without rushing

It is especially worth paying attention to the connection points. So, for example, pipes made of metal are more likely to leak at the seams

You have found the leak, but what to do next? We need to start fixing this problem.

How does this happen? The detected leakage area is repacked, new gaskets and seals are installed. Be sure to install new parts a little thicker than the previous ones. If it turns out that the pipeline is severely damaged, then it is worth replacing with a new one.

Tools and materials

To perform this repair operation, you cannot do without the necessary materials and tools.
Before soldering the car's expansion tank, you need to prepare:

soldering iron with a flat tip, power 40 W;
a piece of fine-mesh brass mesh;
metal scissors.

A soldering iron can be used with a higher power, but then you will need to be careful when working so that the plastic material is not pushed through at the places where the metal mesh is soldered. The brass mesh can be removed from the car’s fuel line tube, which is located directly in the tank

This mesh is used in the car's power system as a filter. After leveling, it can be used as a reinforcing layer to eliminate expansion tank leaks

The brass mesh can be removed from the car's gas line tube, which is located directly in the tank. This mesh is used in the car's power system as a filter. After leveling, it can be used as a reinforcing layer to eliminate expansion tank leaks.

After the preparatory work has been completed and the location of the antifreeze leak has been determined, the tank is thoroughly dried to remove any remaining moisture.

How to solder a crack?

It is not recommended to use even high-quality glue for such car repairs yourself.

High humidity, temperature and significant pressure do not allow high-quality repair of the expansion tank using such substances.

It is much more reliable to eliminate tank leaks by soldering. Plastic easily melts even at a relatively low temperature, so you can use a regular soldering iron to perform the operation.

The soldering process is carried out in the following sequence:

The tank is placed on a flat surface with the crack facing up.
The soldering iron warms up to operating temperature.
A metal mesh, which must be cut in advance so that its length and width are slightly larger than the crack, is applied to the damaged area.
Using a soldering iron tip, the mesh is soldered into the plastic along the entire length of the crack.

Basic repair methods

When using a tank, the plastic is subject to constant deformation - it contracts and expands due to constant temperature fluctuations. Thermal effects and pressure influences provoke the appearance of cracks in the structure of the material.

At the same time, plastic is used for the manufacture of expansion tanks, which does not react with adhesives. Therefore, it is almost impossible to perform high-quality gluing of such surfaces. In this regard, soldering is most often used to repair this car part. A sealant or adhesive may be used as a temporary measure.

Soldering

Most often, cracks and crevices in the plastic of the expansion tank are sealed using reinforcing metal mesh.

Cold welding

The use of cold welding is justified as a temporary measure. With its help, it is possible to repair cracks in order to get to a car service center.

Sealant

Sometimes a special sealant is used to repair the expansion tank. However, this tool can also hardly be called reliable.

The leak must be fixed immediately

If a fuel leak is detected in the area of the gas tank, you should stop using the vehicle for the safety of yourself and others. Repairs should be carried out on a removed and thoroughly washed container. Thus, it is possible to conduct a complete inspection of the product that was pierced and accurately determine the location of the problem area. Most often, these are longitudinal cracks or destruction of the weld connecting the elements of the fuel system, which are a consequence of mechanical influence from the outside.

Preparing a tank for repair includes a number of operations:

Draining fuel. There is a drain neck at the base of the gas tank; by unscrewing the lock plug from it, you can drain the fuel;
Washing the container. At home, caustic soda is used for washing, using it in proportion - two glasses per 10 liters of warm water. The mixture is poured into the tank and left for at least 5 minutes, after which the container is shaken and the liquid is drained. The procedure is repeated at least 3 times;
Drying. This operation must be carried out very carefully. It can be done naturally, but it will take a lot of time. It is better to use an industrial hair dryer, thereby ensuring the effect of air blowing under pressure.

Troubleshooting Methods

Depending on the breakdown, the nature of the repair will differ. If the problem is caused by coolant leakage, then this can be identified, for example, by leaking pipes. Fluid emissions will also be clearly visible in the form of colored streaks on the expansion tank near the plug. In the event of minor damage to the radiator, finding the location of the leak will not be so easy, since the device is blown by a counter flow of air and leaks cannot always be detected.

To simplify the leak detection procedure, it is recommended to fill the system with coolant with a fluorescent additive. Using an ultraviolet lamp you can easily detect the slightest smudges.

Any malfunctions that occur can be resolved as follows:

If problems arise with the expansion tank plug valve, you can try to clean and rinse it. No results will indicate the need to replace the part.
If cracks appear on the tank, it will have to be replaced. Sometimes the expansion tank is restored by soldering, but this option is unreliable, since with the next pressure surge the housing may burst again.

Video: how to get rid of air in the cooling system

If any malfunction occurs on the road, you can add antifreeze or, in extreme cases, water and get to the nearest car service center. The exception is a blown head gasket. In case of such a breakdown, you must call a tow truck to transport the car.

Most of the problems that cause coolant to squeeze out of the expansion tank can be fixed on your own. To replace pipes or pumps, you do not need special tools or skills. Repairing more serious damage, such as replacing the cylinder head gasket, will require certain skills, but this procedure can also be performed in a garage without specialized equipment.

Source

Liquids for filling into the tank

Today's cars, built with the widespread use of new technologies, are very demanding of all process fluids, including coolant. The list of requirements is as follows:

the liquid must boil at a temperature not lower than 110 ° C;
freezing threshold - from minus 20 to -60 ° C depending on environmental conditions;
no foaming upon contact with the pump impeller, minimal viscosity;
the liquid must contain non-aggressive additives that prevent the appearance of scale on metal parts;
the chemical composition should not change for 3 years or 60 thousand kilometers.

Antifreeze is a purely domestic product, synthesized during the USSR

All of the above requirements are met by antifreeze or antifreeze, which is the same thing. The name antifreeze comes from the English word antifreeze, which means “non-freezing”. Antifreeze is a substance created on the same basis from ethylene glycol in the former USSR. The word consists of the abbreviation TOS (technology of organic synthesis) and the ending “ol”, inherent in the names of chemical preparations.

The base of antifreeze and antifreeze is the same - water + ethylene glycol in different ratios. Differences between products from different manufacturers may lie in the package of inhibitory additives, so it is not advisable to confuse liquids. There will be no fatal consequences, but some substances can neutralize the effect of others and the anti-freeze properties will deteriorate. In this case, the color of the liquid does not matter - it is just a dye.

You can use distilled water to fill the tank in the following situations:

to dilute antifreeze concentrate to the desired freezing temperature;
in case of an emergency - complete or partial loss of coolant en route;
for the purpose of washing.

The color of antifreeze does not affect its properties; the additive package is important

Distilled (desalted) water does not meet the above requirements: it freezes at zero temperature and boils at 100 °C. Therefore, it is poured temporarily or as a solvent for antifreeze.

It is unacceptable to pour tap water saturated with salts into the expansion tank. An exception is the breakdown and loss of antifreeze on the way and the absence of a car shop nearby. Fix the leak, fill the cooling system with tap water and get to a garage or service station, then drain it immediately. Otherwise, deposits will form on the inner walls of the water jacket of the engine and other units, impairing heat transfer.

Baxi Main 24 Fi - water is dripping from the expansion tank nipple

Post by vendogs » May 16, 2022, 12:08 pm

Boiler Baxi Main 24 Fi. Product code BSE436243652.

I noticed a drop in pressure a couple of days ago. Top-up does not help; per day the pressure drops by 0.3-0.4 atm. I started looking for leaks in the heating system: the radiators and pipes were dry. I climbed into the boiler and saw drops of water from below on the round expansion tank. I climbed up and saw how the nipple was snotty and squeezing drops of water.

Question: What should I do? Change RB? . It seems that the same rubber membrane has torn, since the boiler itself is visually like new. Google https://service.baxi.ru/info/spare-code. 5D=5663880 are they expensive or can I get a used one somewhere?

Baxi Main 24 Fi - water is dripping from the expansion tank nipple

Post by Starik » May 16, 2022, 01:21 pm

Baxi Main 24 Fi - water is dripping from the expansion tank nipple

Post by vendogs » May 16, 2022, 7:46 pm

Yes. I thought about this too. Used is a so-so option.

I noticed that RBs that use the Baxi service with number 5663880 and a BAXI sticker cost about 7,000 rubles

Baxi Main 24 Fi - water is dripping from the expansion tank nipple

Posted by bullet0823 » May 16, 2022, 9:07 pm

Baxi Main 24 Fi - water is dripping from the expansion tank nipple

Post by vendogs » May 16, 2022, 10:15 pm

Also an option. I agree, there will be fewer problems with it than if we change the original tank. But there is a shortage of space in the kitchen, and I have no idea where to put it.

What if you just turn it off? I have this boiler, designed for a house of 200 m2, in a 1-room apartment, it heats the kitchen and room. This is a total of 20 ribs of cast iron radiators and a small heated towel rail. It is hard to believe that the thermal expansion of water in heating mode will give a significant increase in pressure in such a small heating circuit. Especially if I keep the cold pressure at the lower limit of the permissible limit (around 0.5 - 0.7 bar).

Source

Membrane replacement process

When the membrane wears out, the following types of work should be performed:

disconnect the tank and drain;
release pressure using the nipple;
There is a membrane in the place where the pipeline is connected. The membrane flange is dismantled. Afterwards the holder is released;
the membrane is removed;
The inner surface of the expansion tank is checked for dirt and rust. If necessary, flushing is carried out;
you need to know that the membrane is sensitive to oils. So it is unacceptable to use them as anti-corrosion agents on the inside of the case.

Methods for eliminating cracks in plastic containers

During the operation of the tank, the plastic experiences repeated deformations: contraction and expansion as a result of temperature changes. Working under conditions of peak temperatures and pressures leads to cracking of the material.

The plastic used in the manufacture of expansion tanks is not capable of reacting with adhesives of any brand. Due to this, high-quality gluing cannot be performed. The following methods for eliminating cracks are most widely used by car owners:

Seal the cracks in the plastic case using reinforcing metal mesh.
Seal the depressurization areas with epoxy resin, cold welding, or special sealant.

The use of cold welding and epoxy is used to seal gaps in the tank for a short time, for example to get to the garage.

About malfunctions and tank repairs

During operation of the machine, the following breakdowns of the expansion tank may occur;

contamination or failure of the bypass valve of the plug;
rupture of the tank body;
Antifreeze leaking from under the cap.

Most car enthusiasts, when a valve or body breaks down, simply replace the part with a new one. This is justified by the lack of time for repairs and the low cost of these spare parts. Although, if desired, the burst plastic of the tank can be soldered, and the lid can be disassembled and cleaned.

Leaks from under the cork occur when the seal is not tight or due to the design features of the container. For example, on VAZ 2110 cars, a stream from the upper small fitting connected to the radiator hits directly into the neck, causing a leak. The solution is to install a more advanced tank from Priora.

Video: tank body repair

A car's expansion tank is considered one of the most reliable parts. They often last the entire life of the car, especially on foreign cars. To avoid having to change the container ahead of time, it is recommended to periodically check the condition of the valve in the lid. If it is in order, then the plastic of the vessel will not burst from high pressure.

Home →

Maintenance and Repair → Repair →

What malfunctions may occur

The expansion tank of the cooling system has such a simple design that it does not even suggest possible breakdowns. It would seem like a plastic container with a lid, why should it fail? But it is the lid that can sometimes cause problems. It contains a pressure valve, the correct functioning of which directly determines the performance of the engine cooling system as a whole.

During operation of a vehicle with a tank, the following malfunctions may occur:

rupture of the container body;
the appearance of a coolant leak from under the cap;
the plug valve is broken or dirty.

If the tank is seriously damaged, for example, due to a rupture, the tank cannot be restored

Many car owners, if the cap or tank breaks, simply buy a new part, due to its low cost and availability. But if desired, these elements can be repaired: seal the container and clean the lid from contamination. If smudges appear, the reason, as a rule, comes down to a loose fit of the lid to the body due to design features.

Most car owners, when a tank or cap breaks, buy a new part so as not to waste time on repairing them

Expansion tank cleaning products

To clean and wash the RB, car enthusiasts use various means - cleaners, solvents, citric acid, washing powder, etc.

If the level of contamination is so great that nothing helps, you can try the following.

Fill the tank 15% with fine gravel.
Fill the tank with warm water up to half and add dishwashing detergent.
Shake the tank with both hands.
Empty the tank and rinse it with water.

The tank should be clean.

You can use ready-made products, for example, DIMER washing concentrate.

In this case, cleaning is carried out as follows.

Fill the tank 15% with DIMER concentrate.
Shake the tank, tapping its body with your hands, and leave for 10 minutes.
Fill the tank halfway with warm water.
Use a long-handled brush to clean the inside walls of the tank.
Pour out the solution and rinse the tank with warm water.

DIMER concentrate is quite effective in cleaning the expansion tank

There are many other ways to clean RB.

Video: flushing and cleaning the expansion tank

A serviceable and clean expansion tank is an important element of the engine cooling system.

Any malfunctions can be easily diagnosed and fixed with your own hands.

To do this, you just need to carefully follow the recommendations of specialists.

How to fix an antifreeze leak

It all depends on why the antifreeze is leaking in your particular case. However, there is a small list of actions that will help you fix this problem yourself.

Defects in hoses and pipes. There is only one way out - complete replacement of these components. You can change them yourself and quickly enough.
Defects in the tank. Buying a new tank is not a difficult task. After this, remove the clamps from the pipes and replace the tank with a new one. We put everything in its place and start the engine.
Thermostat malfunction. You can replace the thermostat yourself, but if you think your skill set is insufficient, then it’s not worth the risk.
Flaws in the radiator. You can remove the radiator yourself and take it to a service center. They will conduct a diagnosis and tell you what to do next.

DIY expansion tank repair

During operation, the expansion tank is constantly affected by deformation: the container contracts and expands due to temperature changes - this is its operating mode. At peak values, cracks appear on the walls of the tank. The problem can be solved in two ways: buy a new tank or repair the old one.

Expansion tank crack

The material used in the manufacturing process of expansion tanks does not react with any adhesives, regardless of brand. This suggests that it will not be possible to properly repair the tank by gluing it. Those car owners who decide to restore the capacity, as a rule, resort to the following methods:

seal the cracks of the case using a metal mesh;
epoxy resin, special sealant or cold welding are used.

Due to the constant exposure of the expansion tank to high pressure and temperature, cracks appear on the vessel over time

It is worth noting that cold welding and epoxy eliminate the problem only temporarily and you will still have to return to repairing or replacing the tank. Some car enthusiasts are wondering what and how to repair cracks in the plastic housing of the expansion tank? To carry out the procedure at home you should:

Some car enthusiasts are wondering what and how to repair cracks in the plastic housing of the expansion tank? To carry out the procedure at home you should:

clean the housing at the crack site with a clean rag or napkin;
degrease the area with solvent and then dry;
cut a piece of brass mesh with small cells along the length of the damage;
apply a strip to the repair site;
Using a heated soldering iron, solder the mesh to the edges of the crack so that a reinforced layer is formed over the entire area of the mesh;
grind the seam;
Apply putty, a layer of primer and paint.

The most common and affordable way to restore an expansion tank is soldering using a fine metal mesh

For the procedure discussed, you will need a soldering iron with a minimum power of 40 W and a flat tip. You can restore the seal of the tank using a special red Done Deal sealant, which is intended for plastic. Before applying the substance, the body is thoroughly cleaned and degreased.

Useful video

Watch an interesting video where a car owner shows how to repair a crack using soldering:

And in this video, the driver demonstrates how he glues the tank using Done Deal 15-minute polyadhesive for plastics and what comes out of it:

Repairs on the road

Repairing an expansion tank with your own hands is not at all difficult, but many motorists are interested in the question: “How to seal the expansion tank on the road”?

If during travel, when it is not possible to apply the above method for repairing the tank, you can temporarily fix the leak using white silicone sealant. To perform this operation you must:

dismantle the tank, empty it of antifreeze;
Dry thoroughly and apply sealant to the crack on the inside of the container;
After applying the sealant, it must be left in place for at least 4 hours, after which the part must be put back in place and movement continues.

Results

So, if you decide to restore a plastic tank yourself, then you should use the following repair methods:

soldering with metal mesh;
special sealant;
cold welding or epoxy resin (temporary).

It will not be possible to restore the seal properly using glue!

People are often interested in how to seal a car's expansion tank. For this purpose, different methods are used. The most common and reliable method of repair is soldering this part of the machine. Thanks to this, it is possible to achieve the most stable fixation. If temporary repairs need to be made, it is acceptable to use glue or sealant. Cold welding is also permitted.

Results

As you can see, it doesn’t matter where you end up. Gas tank repair can be carried out even in the field

For this, improvised means such as laundry soap or a plastic bottle are sufficient. Even simple glue can become a good sealant if you find an unnecessary rag.

Many modern vehicles have plastic elements in their design. There have been attempts to produce bodies entirely based on plastics, but due to globalization, automakers continue to stubbornly use metal as the basis for their production. But some automotive elements made of plastic are gradually replacing the usual metal products.