The brake fluid is rarely checked up by many drivers. To be honest, most drivers don’t even know that they should do it or even where the brake fluid reservoir is.

However, after the engine oil check and transmission oil check, this is the most important one.


How does the brake system work?

The car brake system is, essentially, a hydraulic system.

Whole system depends on pressure that you make by pressing the brake pedal.

Not enough fluid in the system equals to lack of pressure which weakens the braking force.

No need to say that this is very dangerous.

For more detailed information on how the brake system works, click here for a great explanation on Wikipedia.


How often should you check the brake fluid level?

Brake fluid is rarely in need of refill unless you’ve had any intervention on the brake system (disc pad or brake shoe replacement, replacement of the brake fluid, brake lines etc).

So, just take a look from time to time and see that the level is between the MIN and MAX mark on the fluid reservoir.

If the brake fluid is low, of course add some. After that, if the level goes down again, check the whole brake system as soon as possible.

Decrease of brake fluid level usually means that you have a problem.

One more tip: most modern cars have connected clutch and brake systems so if there is a constant lack of brake fluid in the container make a check on the clutch system too.

The procedure is no more complicated than adding coolant or adding wiper fluid. So, find the reservoir, open it, add fluid and close the container tightly.

Buy the proper braking fluid.

Before starting: be sure to buy the proper one, preferably same as it was before.

You can find the proper specifications in a owners manual, on the internet or simply ask at the car parts shop

All brake fluids are classified by DOT grading.

You’ll find this grading on the bottle so you can’t make a mistake. on the side of the bottle.


Procedure for adding brake fluid.

  • Find the reservoir

It will have a distinct cap color-mostly yellow. On the visible side it has engraved markings for the minimum and maximum fluid level.

brake brake fluid


  • Open the reservoir-turn the cap counter-clockwise.



  • Refill the fluid ; fill until it’s between the“min” and “max”level.

Don’t over do it as over filling can damage the brake system (mainly the brake cylinder)



  • Return the cap-turn clockwise. Tighten it properly.

This is important so no air gets inside the brake system. If some fluid spills around, wipe it right away as it is aggressive towards other materials and can cause damage.