Will Brake Fluid Damage an Engine? Technical Guide

Engine oil is needed for lubrication and cooling. It has properties that make it proper for this purpose. Brake fluid, on the other hand, has properties that make it suitable for the braking system.

In this article, we are trying to determine will brake fluid damage an engine? We will also find out what happens when brake fluid is put in an engine instead of the right engine oil. You will also learn what happens if you put brake fluid in engine oil. 

will brake fluid damage an engine

Will brake fluid damage an engine?

Yes, brake fluid can damage an engine. Brake fluid is not a lubricant. When it is used instead of engine oil, components can get damaged. The gasket will absorb the brake fluid and bulge. Then even the seals used will get worn because brake fluid is meant for a different purpose.

You may expect different problems when you allow brake fluid in gas tank lines. To sum up, dot 4 brake fluid can damage an engine when you use it instead of the regular motor oil.

What happens if you accidentally put brake fluid in an oil tank?

When you put brake fluid in an oil tank, destruction is immediately set in motion. Brake fluid is an enemy of rubber. It will therefore cause the rubber seals to get brittle. The brittle seals will crack and fail in the process. This can lead to severe leakages around your engine. Even the gasket will break, and leakages will follow immediately.

On the other hand, when you see oil in brake fluid lines, it should move you to take corrective measures. The damage will still be the same whether you do it accidentally or deliberately. Sometimes, your engine may take some time before showing signs of wear.

What happens when you mix brake fluid and oil?

Mixing brake fluid with oil brings two different liquids together. Engine oil becomes less effective and loses its correct viscosity. Brake fluid always can accommodate moisture. Engine oil is intolerant to moisture. That is why such a mixture has the potential to damage the engine.

Additionally, brake fluid in engine attacks rubber. This means that the rubber seals around your engine will be damaged. Correcting this mistake calls for removing every last drop of the brake fluid. You also need to change the seals. Otherwise, the engine will no longer seal as expected.

Will brake fluid clean an engine?

No, brake fluid cannot clean the engine. It will actually do the opposite. The engine does not need brake fluid. Therefore, brake fluid contaminates the system. You can only clean the engine with the right cleaning agents or liquid. If you use brake fluid to clean the system, it will simply cause damage. There is no better way to put it apart from bluntly stating that it is not a cleaning agent. Brake fluid is added to work only within the braking system. By considering it as a cleaning agent, you end up with brake fluid contaminated with oil. 

What to do after putting brake oil in an engine?

Suppose you have already put brake fluid in that engine. What next? It is time to remove the foreign fluid. Later, you will also need to flush or clean up the system. There are several things you can do to correct the situation. You can follow the following steps :

Park your car on level ground and block it

This is the first step you must take. If you have a chance to put it on a pit, you can do so. This is a better option. Otherwise, ensure that the surface is hard enough and level.

Jack the Vehicle to create space under it

Jack the car up and block the rear wheels. Remember that you are jacking the front side of the vehicle. Make sure you create enough space for you to go under.

Drain the brake fluid from the engine

Get a creeper and roll under the vehicle. Put the drain pan under the drain plug and loosen it. The brake fluid will be collected by the drain pan.

Add flushing liquid

This liquid should now come in to ensure that there are no residuals of the brake fluid remaining. Kindly note that you can only do this after the brake fluid is completely drained.

Crank the engine for a while:

After adding the flush liquid, you can crank the engine briefly. Do not allow it to start running.

Remove the flush liquid:

In this step, remove the cleaning agent or flush. Drain it out completely.

Put the correct oil in the engine:

Finally, fill the right oil in the engine. Remember to secure back the drain plug before putting in the correct oil.


Will brake fluid damage an engine? Putting brake fluid in an engine can be dangerous. You can damage your engine and incur high costs to correct it.  Otherwise, the question is, where do you put the brake fluid on a car? Brake fluid is for the braking system, and there are no two ways. When you do things right, you protect the engine against imminent damage. You can correct the situation if you accidentally put brake oil in an engine. In the end, the engine will still run normally. 


Mr. Shafiqule Islam is a graduated Mechanical Engineer and has more than 15 years experience of repairing and maintenance of different brand vehicles like Toyota, Mitsubishi, Ford, Mercedes, BMW etc. He is also giving training to Mechanics. He has started writing to share his practical knowledge to Vehicle Owners, Drivers and Mechanics to keep their cars at best fit.

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