How to check the brake fluid level

Video: How to Check Your Car’s Brake Fluid

Content

Method 2 of 2: Checking the condition of the brake fluid
Tips
Warnings
What do you need

1 Open the hood of the car. It is best to do this when the car is on a level surface and the engine is cold.

2 Locate the brake master cylinder. In most cars, it is located in the rear of the engine compartment, on the driver's side. There is a reservoir above the cylinder itself.

3 Check the liquid level in the reservoir. In most modern cars, this tank is transparent and is also marked "Min" and "Max"; the liquid level should be somewhere in between. In cars that were built before the 1980s, this reservoir may be metal, so you will have to remove the tank cap. (Newer covers screw on and off; on older machines you will need to use a screwdriver.)

4 Top up the brake fluid reservoir if necessary. Add liquid carefully, if something spills - wipe it off immediately! Brake fluid is toxic and corrosive.

Use brake fluid with the DOT specification recommended in the owner's manual. There are three main ones: DOT 3, DOT 4 and DOT 5, each with its own properties. It is possible to use DOT 4 fluid for some vehicles requiring DOT 3, but never vice versa, DOT 5 can only be used in vehicles requiring this specification.

5 Put back the cover and close the hood.

If the brake fluid level is significantly below the "Min" or "Add" mark, the brakes should be checked for wear. As the brake pads wear out, brake fluid can leak from the pipes into the brake calipers.
It may also be that the reservoir is full, and the fluid does not reach the master cylinder of the brake system. If the reservoir is full, but the brake pedal still falls, take the car to a service.

Method 2 of 2: Checking the condition of the brake fluid

1 Check the color of the liquid. She is usually brown. If the fluid appears dark or black, it may need to be replaced, but further testing needs to be done.
2 Submerge a chemical test strip in the brake fluid. Corrosion inhibitors deteriorate as the fluid ages. Test strips check for copper in the brake fluid; the higher the level, the more worn out the retarders.
3 Check the moisture content with an optical refractive meter. Brake fluid is hygroscopic, i.e. over time, it absorbs moisture, which dilutes the fluid and weakens its effectiveness, causing the brake system components to corrode. After 18 months, the water content in the brake fluid can be 3%, which reduces the boiling point by 40-50%.
4 Determine the boiling point of the brake fluid using an electronic tester. The new DOT 3 fluid should have a dry boiling point of 205 degrees Celsius and a wet boiling point of 140 degrees. DOT 4 liquid - 230 and 155 degrees, respectively. The lower the boiling point, the less effective the liquid is.
- Your mechanic should have both an optical refractive index meter and an electronic brake fluid tester, so he can easily check everything during a routine car check.

Tips

Most manufacturers indicate when the brake fluid should be changed. Check the user manual for the exact information on your model.

Warnings

In addition to the brake or ABS indicators that light up, the brake pedal can sink, be too hard, pulsate, grab, make noise, the car can go to the side, when braking, a burning smell can appear, in all these cases, take the car to the service.