How to check the expansion tank cap for proper operation of the valves
Content
A car is a mechanism in which every detail performs its task. Failure of one can lead to disruption of all systems. Few people know how important such an element is in the internal combustion engine (internal combustion engine) of a car as the reservoir cap of a closed-loop cooling circuit, which will be discussed further.
On the one hand, it may seem that this cork simply prevents antifreeze or antifreeze from splashing. Not so simple! Believe me, if this part in the engine becomes unusable, the main components of the car will have problems. Accordingly, your wallet will have to lose weight.
What is unusual about the coolant reservoir cap
It would seem that it is an ordinary cork that closes a container with liquid, but basically all the negative comes from the non-liquidity of this ICE element. In this element of the system there are 2 valve mechanisms (regulator). One relieves excess pressure, and the other, on the contrary, pumps air to increase pressure.
When the system warms up while the vehicle engine is running, the valve releases excess pressure to keep the system running. When the engine cools down, the pressure drops in the cooling circuit. To prevent the nozzles from starting to compress and the system not to become inoperable, another regulator comes into play, increasing the entry of air from the atmosphere into the system.
A lot of important fact, connected specifically with the cover of domestic production, is that this part sometimes needs to be finalized by yourself in garage conditions or at home. From the factory, the springs have many turns, thereby forming a tight contact between the valves and the cover.
Therefore, they cannot perform their functions in full. Drivers-needleworkers correct the defect on their own. If you do not understand the technical part of the car, then it is better to contact a service center or replace the part.
How the cover is arranged and how it works
This element has a simple structure:
- Plastic cover (shell);
- 2 springs with valve;
- Cork with holes;
- Rubber compressor.
The principle of operation of the plug is also very simple: in case of excessive heating of the cooling circuit, the regulator releases excess pressure. On the contrary, if it is low in the circuit, the regulator passes atmospheric air through itself to build up pressure. Thanks to the inlet valve, the cooling circuit is constant.
If one of the elements of the cooling circuit is leaking, then air will be in the system. The result is an airlock. Where it leads? Overheating of the internal combustion engine or violation of circulation in the entire system.
Symptoms of a malfunction
In the event of an internal combustion engine overheating, drivers try to find a problem under the hood, in particular, they check the cap of the cooling system reservoir, which keeps the pressure in the cooling circuit. The sad result of overheating can be antifreeze (antifreeze), which can get into the engine itself.
The main and main problem is the malfunction of the internal valve. In case of violation of its performance, air enters the system, as a result of which an air plug is formed. It does not allow the antifreeze (antifreeze) to circulate properly inside the sealed cooling circuit.
If the cap or the intake valve itself is faulty, the following may occur:
- Violation of the integrity of the hoses due to exceeding the service life or low-quality materials;
- Melting of the thermostat shell;
- The formation of a leak in the radiator;
- Violation of the integrity of the tank in which the coolant is located.
Why does antifreeze press from under the coolant tank cap
The main reason for the release of antifreeze from the expansion tank is a plug malfunction.
In addition to the locking element itself, there are a number of other reasons due to which coolant may come out:
- A crack in the body of the tank in which antifreeze is located;
- Depressurization of the cooling circuit, as a result of burnout of the head gasket of the engine block;
- Poor pump performance. Because of it, the circulation in the cooling circuit does not allow the insides to cool to an acceptable temperature;
- Damage to the thermostat;
- Cracks in the radiator;
- Cracks in hose and pipe connections.
How to properly check the cover and fix the problem
First, take a look at the part for damage. Indiscretion is the main factor that can harm the entire cooling system and the engine as a whole. When buying a new cover, you should check it for damage, as marriage from the store is possible.
If the cover is without external defects, it should be tightened and the engine started. The internal combustion engine must run to reach operating temperature. After this action, you need to carefully scroll the plug counterclockwise. A hissing sound should appear. From here you can understand that the cork really works as it should.
While the engine is running, check the thick pipes of the cooling circuit. If the pressure in the system is incorrect (low), then the nozzles on the running engine will be depressed.
Unscrew the cap of the expansion tank and squeeze the pipe. Then close the plug and release the pipe. It should come to its original shape at the pressure in the cooling circuit everyday for the power unit.
The best option for testing the tank plug of the system is a pump with a measuring indicator of the pressure level in the circuit.
Diagnostics of the element on cars of models Kalina, Priora, Gazelle
To understand the serviceability of the cover, you need not only to check its condition, but also to diagnose it with atmospheric air. In special service centers, pressure pump equipment is used that pumps the required amount of atmospheres. They can calculate the performance of the valves in the cap of the expansion tank.
For example, drivers on Priora do not have a special pump, how can they check the operation of the expansion tank cap?
Diagnosing the quality of the plug will be less accurate, but you can still detect malfunctions of the valves:
- First, turn off the engine.
- As the power unit of the car stands a little, unscrew the plug from the neck of the expansion tank.
- Inspect the part for obvious defects. Check the rubber seal inside the cover.
- If the plug is in good condition, put the cap back on and start the engine again.
- Wait until the engine reaches normal temperature.
- Take the cork in your hand and gently unscrew until hissing air. If it appears, then the valves in the plug are ready for further operation.
- Shut off the engine and let stand.
- Inspect the hoses adjacent to the circuit. If they are drawn in, then the pressure in the system is below normal. Accordingly, the vacuum valve cannot cope with pressure regulation.
This is the main instruction for AvtoVAZ models. This instruction is suitable for Kalina, Priora and Gazelle brand models.
Checking the cover on VAZ 2108 - 2116 models
For each generation of cars, starting with the "eight", the technology for examining the plug of the tank of the system does not differ much. Let's figure it out in order.
Inspection of the element on the VAZ 2108/2109
The structure of the "eights" and "nines" allows you to check the readiness of the cover valves in just 60 seconds.
The procedure is as follows:
- Open the hood of the VAZ. Wait a couple of minutes for the internal combustion engine to stand a little after operation.
- Loosen the cap on the reservoir of the cooling circuit.
- Squeeze the inlet pipe that there is strength.
- At the same time as compressing the hose, tighten the plug on the neck.
- Then release the tube.
It straightens up after compression, the valves are all right and you have nothing to fear.
Diagnosis of traffic jams on VAZ 2110-2112
The technology for checking this part is exactly the same as for all models of VAZ cars. The main difference is that when you open the lid, the mechanism that is installed in it may fall out.
This is not a malfunction, just a manufacturing defect. If it is not installed correctly, then this contour element, alas, will not work for long.
Checking the part for the cooling circuit on the VAZ 2113-2116
It's simple, fellow motorists:
- Start the engine.
- Open the hood and start unscrewing the system reservoir cap.
- If, at the very first manipulation, the sound of gases is heard from under the lid, everything is in order and there is nothing to worry about.
The developers of new models of the Russian brand create newer and more complex mechanisms. Therefore, checking the performance of valves in artisanal conditions may not bring results. In this case, you will have to contact the specialists in the service. There you will be able to diagnose the reservoir cap of the cooling system using special equipment.
What can be concluded
The expansion tank cap is an element that is vital to the engine. It plays the role of not only a locking device in the engine compartment, but also a kind of regulator. The plug regulates the pressure in the cooling system, which allows the power unit to work properly and flawlessly.
But if there come moments that make you doubt that the cover is faulty, then you should check it without fail. All methods and procedures are described above.
In cases where the cover is in poor condition, it is recommended to purchase a new one. The best option is to buy in a specialized car shop, exactly the brand that you own.
The original cover will last longer than those purchased in the markets. Having installed the original, you can not worry about the cooling system for several years.
