How to remove air lock in a car cooling system

How to remove the air plug from the cooling system

The presence of air jam in the cooling system is fraught with problems both for the engine and other components of the car. In particular, overheating may occur or the heater will not heat properly. Therefore, it is useful for any motorist to know how to expel the air plug from the cooling system. This procedure is quite trivial, so that even a novice and inexperienced, motorist will be able to do it. Due to its importance, we will talk about three methods of air removal. But first, let’s talk about how to understand that there are air locks and the reasons for their occurrence.

Removing an air lock

Symptoms of Breathlessness

How to understand that there is an air lock in the cooling system? When this phenomenon occurs, there are several typical symptoms. Among them:

  • Problems in the work of the thermostat . More specifically, if after starting the engine cooling fan turns on very quickly, it is very likely that the thermostat is out of order. Another reason for this, may be that air has accumulated in the pump spigot. If the thermostat valve is closed, the antifreeze will circulate in a small circle. Another situation is possible, when the coolant temperature needle is at “zeros” when the engine is already warmed up enough. Here again two options are possible – the thermostat malfunction, or there is an air lock in it.
  • Antifreeze leak . It can be checked visually by traces of the drip on separate elements of the engine or running gear of the car.
  • Pump starts making noise. With its partial failure there is an extraneous noise.
  • Problems in the operation of the heater. There are many reasons for this malfunction, but one of them is just the formation of an air lock in the cooling system.

If you find at least one of the signs described above, it is necessary to carry out a diagnosis of the cooling system. However, before this, it will be useful to understand what caused the possible problems.

Causes of air clogs

A chilled cooling system can be caused by a number of malfunctions. Among them:

    Leakage in the system . It can occur in a variety of places – on hoses, fittings, pipes, tubing and so on. Leakage can be caused by mechanical damage to its individual parts, their natural wear and tear, a decrease in pressure in the system. If after you have eliminated the air plug air appears in the system again, it means that the system is depressurized. Hence it is necessary to make diagnostics and visual inspection in order to find the damaged place.

Mazda 6 Air Filter Replacement Video Instruction

Antifreeze filling

Fill antifreeze with a thin stream

Each of the above-mentioned causes may damage parts and mechanisms of the car. First of all, the engine suffers as its normal cooling is disturbed. It overheats, due to which the wear increases to critical. And it may lead to deformation of its separate parts, failure of sealing elements, and in especially dangerous cases even to its jamming.

Also air shortage leads to the bad work of the heater. Causes of this are similar. Antifreeze does not circulate well and does not carry enough heat.

Next, let’s move directly to the methods by which you can remove the air lock from the cooling system. They differ in the way they are performed, as well as in their complexity.

Methods of removing the air plug from the cooling system

How to expel the air plug from the cooling system VAZ classic

There are three main methods by which you can remove the air plug. Let’s list them in order. The first method is perfectly suitable for VAZ cars . Its algorithm will be as follows:

  1. Remove from the engine all protective and other elements that may prevent you from getting to the coolant expansion tank.
  2. Disconnect one of the pipes that are responsible for heating the throttle assembly (whether direct or reverse).
  3. Remove expansion tank cap and cover neck with loose cloth.
  4. Blow on the inside of the tank. This way you will create a slight overpressure, which will be enough for the excess air to escape through the branch pipe.
  5. As soon as antifreeze comes out of the branch pipe opening put the branch pipe on immediately and preferably fix it with a clamp. Otherwise air will get back into it.
  6. Close the cap of an expansion tank and assemble back all elements of engine protection, removed earlier.

The second method is carried out according to the following algorithm:

  1. Start the engine and let it run for 10. 15 minutes, and then turn it off.
  2. Remove the necessary elements to get to the coolant expansion tank.
  3. Without removing the cap, disconnect one of the pipes on the tank. If the system was bled, air will start to come out of it.
  4. As soon as the antifreeze is flowing, immediately reattach the socket and secure it in place.
Oil is leaking or how to fix a crack

Be careful when doing this as the antifreeze temperature can be high and go up to +80. 90°С.

The third method to remove the air lock from the system is as follows:

  1. It is necessary to put the car on an elevated position so that its front is higher. It is important that the radiator cap is higher than the rest of the cooling system. While doing this, put the car on the handbrake or, better yet, place chocks under the wheels .
  2. Allow the engine to run for 10. 15 minutes.
  3. Unscrew the caps from the expansion tank and radiator.
  4. Periodically press the accelerator pedal and add coolant to the radiator. Air will be coming out of the system. You will see air bubbles in the system. Continue this procedure until all the air is gone. You can turn on the heater to maximum when doing this. As soon as the thermostat opens the gate fully and very hot air is coming into the cabin, it means that the air has been removed from the system. At the same time, you need to check for bubbles coming out of the coolant.

As for the last method, in cars with automatically activated cooling system fan, you can even not speed up, but calmly let the engine heat up and wait for the fan to turn on. At the same time the movement of the coolant will intensify and the air will escape from the system due to the circulation. It is important to add coolant to the system so that the system does not become clogged again.

As you can see, the methods of how to get rid of the air lock in the engine cooling system are quite simple. They are all based on the fact that air is lighter than liquid. Therefore, it is necessary to create conditions in which the air plug will be forced out of the system under pressure. However, it is best not to bring the system to that state and take preventive measures in time. About them we will tell further.

Just an interesting fuel gauge scheme

General recommendations for prevention

The first thing you should pay attention to is the level of antifreeze in the cooling system . Always check it, and top up if necessary. And if you have to top up the coolant very often, it is the first call, indicating that there is something wrong with the system, and additional diagnostics is needed to determine the cause of malfunction. Also check for antifreeze leakage stains. It is better to do it on the observation pit.

Do not forget to periodically clean the cooling system. How and by what means to do it you can read in the relevant articles on our site.

Try to use the antifreeze, which is recommended by the manufacturer. And make your purchase at verified licensed stores, minimizing the chance of getting fakes. The thing is that a low-quality coolant in the process of multiple heating may gradually evaporate, and instead of it air cork is formed in the system. Therefore, do not neglect the requirements of the manufacturer.

Instead of a conclusion

In conclusion, I would like to note that in the case of the occurrence of the described signs of aeration of the system, it is necessary to perform diagnostics and check it as soon as possible. After all, the air plug significantly reduces the efficiency of the cooling system. Because of this, the engine works in conditions of increased wear, which can lead to its premature failure. Therefore, try to get rid of the plug as quickly as possible upon detection of aeration. Fortunately, even a novice motorist can do it, because the procedure is simple and does not require the use of additional tools or devices.

Simple methods to expel air after changing the coolant

The procedure should be carried out slowly, since hot antifreeze can burn your face and hands. In modern cars, purging is carried out through the radiator – the thermostatic plug does not allow to do it through the expansion tank.

How to replace the bulbs in the tail light of the Lada Granta liftback

How to remove air from cooling system

To expel air from heating system is an obligatory regulation requirement after its servicing. Air gaping in tubes causes a number of problems, leading to car’s breakdown.

Can the antifreeze fluid leak because of an air lock?

Owners of Russian cars most often face the problem of antifreeze squeezing out of the cooling system. In the majority of cases it may be caused by

  • with a faulty discharge valve on the cap of the expansion tank;
  • unskilled replacement (refilling) of the coolant.

At service stations the procedure is performed with the help of an apparatus delivering antifreeze under pressure, which excludes airlocks. If topping up is carried out without using the machine, excess air can form in the system.

After a plug appears, the engine is not cooled sufficiently:

  • it overheats or does not supply warm air at all;
  • Heating of the passenger compartment is not working properly.

Also disturbed the circulation of the coolant – it is squeezed out of the cracks in the hoses in the places of loose adherence of the connecting elements, from under the cover of the tank.

How to expel the air from the cooling system

The way to remove the air plug depends on the design of the car, the volume of trapped air, the availability of the necessary equipment.


The method is the easiest to perform, can be used in the absence of the necessary tools at hand, but not always effective.

How to fill the tank

Pouring the liquid into the tank

After replacing the coolant, you can expel the air by following the sequence of actions:

  1. Position the vehicle on a level surface.
  2. Apply the handbrake.
  3. Place a jack under the front wheels and raise the car to the highest possible height (at least half a meter).
  4. Remove the cap from the expansion tank.
  5. Start the engine.
  6. Set air blowing on maximal speed.
  7. Start slowly pouring antifreeze till it reaches maximum level.
  8. Hold the accelerator pedal up to 3 thousand rpm until the engine warms up.
  9. Firmly squeeze the coolant hose from the radiator (being ready to spill coolant) in order to squeeze out the air.

Repeat the last step until the plug is removed. It is advisable to monitor the engine temperature to prevent overheating.

How to polish a car properly

Blowing without equipment

The method is more effective than the previous one, but requires more accuracy. All actions are carried out on the warmed up engine (not less than 60 ºС):

  1. Fill the brine to the required level.
  2. Remove the upper branch pipe (for injector engine – from throttle, for carburetor engine – from intake manifold), and the end put in a clean container.
  3. Bleed out the air from the antifreeze by blowing hard into the expansion tank. Blow until the air bubbles stop appearing in the poured out fluid.
  4. Fasten the hose in place.

The procedure should be carried out slowly, since hot antifreeze can burn your face and hands. In modern cars, purging is carried out through the radiator – the thermostatic plug does not allow to do it through the expansion tank.

Blowing with a compressor

The method is used in service centers – a special compressor is used, which delivers air under pressure. In garage conditions it is allowed to take a car pump.

How to remove the air plug in the cooling system

How to remove the air plug in the cooling system

The procedure is similar to the previous method, it is required to monitor the pressure (because of the powerful flow can kick out not only air from the antifreeze system, but also the coolant itself).

Full replacement

It is necessary to remove the existing liquid and pour a new one, observing the technical regulations. To prevent the situation from repeating, you need to flush the system with a cleaning composition, fill it with antifreeze with a compressor, check the formation of air bubbles on the drain. At the end of the procedure screw the lid on tightly and make sure all connections are secure.

Prevention of air lock causing engine overheating

To eliminate cooling problems, you must follow the recommendations:

  • check the antifreeze level periodically;
  • Use only tested coolant (coolant);
  • When changing coolant it is recommended to pay attention to the color of coolant and buy new coolant of the same color;
  • Any problems must be eliminated as soon as they occur, without waiting for the situation to get worse.

The main recommendation of the specialists is to have the system serviced by a certified technician, and not to pour water into the system.

( No ratings yet )
Like this post? Please share to your friends:
Leave a Reply

;-) :| :x :twisted: :smile: :shock: :sad: :roll: :razz: :oops: :o :mrgreen: :lol: :idea: :grin: :evil: :cry: :cool: :arrow: :???: :?: :!: