Antifreeze leaks from the car's expansion tank: causes and consequences


July 9, 2022, 08:37 | Auto

What it could mean for a car.

Antifreeze is leaking from the expansion tank of the car: causes and consequences

It often happens that antifreeze (coolant) comes out of the expansion tank, but it is unknown where, there are no drips or drops under the car, informs Ukr.Media.

What to do and why this happens. Let's figure it out.

If antifreeze comes from the tank, and it does not flow anywhere, that is, it seems that the system is in perfect order, this is a bad sign and it entails a serious breakdown. You cannot drive such a car. Every kilometer leads to an overhaul of the engine, and what's worse, it can simply jam.

Obvious problems of lowering the level

< em>Engine radiator

First of all, you need to check the engine radiator. To do this, it is enough to look at it, as well as look at the leaks under the car, if it is punctured, there will be red, green or blue drops. Of course, you can try to solder or clamp the radiator tubes, but the plastic component (sides) is often damaged, you can't do anything here, it needs to be replaced.

Stove radiator

Check the stove radiator. Almost the same picture, only the interior heater leaks, it is more difficult to diagnose, because the coolant will drip onto the seal (carpet covering) in the interior. But the reasons for the determination are simple, if it smells like antifreeze in the cabin (a sweet smell), but there is none outside. If the glass sweats even in dry weather, and the coating on the glass is oily. Liquid is coming out of the tank, it means that you have covered the radiator of the heater, of course if you remove the plastic (decorative) protection of the instrument panel, you will see that it is dripping somewhere. We also do it, or restore it, or if it is not possible, change it.


They wear out over time, because they expand every time (when the engine is heated) and narrow (when cooling), such work sooner or later will damage them, they will not be able to hold the pressure and will tear them. Of course there may be minimal damage, but the flow will be constant. It is useless to do hoses, it is better to replace them immediately.


The same situation as with the hoses, they are metal here and usually last a long time. But there are situations when they also leak.

Thermostat and pump

These are two mechanisms designed to pump and regulate the flow of coolant, the body is made of metal or plastic and often they leak, it happens from time to time. They are only replaced.

The cover of the expansion tank and the tank itself

The cover is a valve, after a certain mileage it also fails if it does not hold pressure, then the antifreeze from the expansion tank may splash out during heating. Also, the tank itself can burst, because it is made of plastic, if the lid is faulty, it can tear.

It often happens that the driver is looking for and cannot find the cause of the leak. And antifreeze can go into the furnace and then into the cabin, and it is quite difficult to determine immediately. To check, put the car on a dry site or in a garage if possible and observe if there are spots in the color of your coolant, then this is definitely a leak.


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