Tips to Diagnose Radiator Expansion Tank Failure in Your Mini

Your Mini is a vehicle that you rely on to get you safely from one place to another. In order for this to happen, you need to make sure that you are keeping up with the required maintenance schedule to keep all components in good working condition. One such part is the radiator expansion tank. You need to be aware of what signs to look for in order to diagnose this failure so you can have your Mini serviced when necessary.

The Radiator Expansion Tank

The radiator expansion tank, also known as the radiator overflow tank, serves a simple but important function. It prevents rust from forming in the cooling system of your Mini.

Rust can form in the cooling system after the engine has been shut off and the air begins to make its way into the radiator. The air is able to get into the radiator, because once the engine has cooled, the coolant will contract in volume, resulting in a drop in temperature and pressure which leaves room for the air. As soon as the air touches any of the parts of the cooling system, rust will begin to form. Once this occurs, the entire system will need to be flushed and the coolant replaced.

So all of that to say, the radiator expansion tank works to prevent rust formulation that air causes when it enters the cooling system. When the engine of your Mini is running, it is heating up the coolant in the radiator, which leads to a building of pressure. When the pressure becomes too much, the coolant will overflow into the expansion tank. When the pressure has decreased, a vacuum is formed in the radiator, and the overflow of coolant is able to make its way back into the radiator, preventing space in the radiator for air to get in and cause rust to form.

Signs of Radiator Expansion Tank Failure

With the radiator expansion tank working properly, you will be saving a significant amount of money because you will not have to flush out your entire cooling system every time air gets in. In order to keep it working as it should, you need to be aware of signs that your Mini will give you that will alert you to radiator expansion tank failure.

One sign for a failed radiator expansion tank is a coolant leak. The main function of the radiator expansion tank is to hold the overflow of coolant. If the radiator expansion tank has failed, then the coolant will leak out. This could be due to a crack in the part. You will be able to tell that coolant has leaked out of your Mini if you see a greenish-colored puddle underneath the front of your vehicle. Coolant also has a slightly sweet smell, so this is another identifier that you can use in order to determine if it is a coolant leak.

Another sign that will indicate to you a failed radiator expansion tank is the low coolant light illuminating on your dashboard. If you are constantly seeing this light come on, you will know that there is an issue with the radiator expansion tank. If the tank is unable to hold the coolant that is forced out while driving, the light will come on, telling you that you need to top off the coolant. If this is something that you frequently have to do, you know that there is an issue with the radiator expansion tank.

One last sign that you will be able to use to diagnose radiator expansion tank failure is overheating. Without the proper amount of coolant in the system, the engine of your Mini will not be able to stay at the required cool temperature. So if you notice that your engine regularly overheats, then the issue is with the radiator expansion tank.

Repairing the Radiator Expansion Tank

The moment you notice any of the above-mentioned signs of a radiator expansion tank failure, it is time to bring your Mini in for repairs. At Germany’s Best Inc., we take a thorough look at your Mini in order to properly diagnose the issue with the radiator expansion tank. We are conveniently accessible from the areas of Berkeley, Emeryville, Piedmont, and Oakland, CA. Once you trust us with this repair, you will drive away happy and can return us with any other repairs that may come up in the future.