If you had to pick one thing your car can't be without (please don't say the cupholder) it would be the brakes. A perfect running car that starts on the coldest mornings and purrs like a milk-faced kitten doesn't amount to much if you can't stop when you need to. That's why you should be sure to take good care of your car's braking system. This includes keeping your brake pads replaced, inspecting your brake rotors and, of course, making sure there is enough clean brake fluid to keep the system operating correctly.

Most, if not all, vehicles on the road today have a brake fluid reservoir that allows you to see through so you can check the fluid level without opening the cap. The brake fluid reservoir will be located toward the back of the engine bay on the driver's side, up high where it's easy to access.

Once you locate the brake fluid reservoir, you will see markings on the side that tell you if you need to add any brake fluid. You may need to clean off a little road grime to see the marks clearly.

If you do need to add some brake fluid, be sure to follow these tips.

If you check the level of your car's brake fluid and discover it low, don't sweat it, you can have things tip-top in no time at all.
Before you remove the cap to the brake fluid reservoir, wipe the area down thoroughly with a rag. Your braking system is sensitive, and foreign materials creeping in can clog or degrade its components. Start off clean and avoid any problems.

With the cap off, slowly add fluid until it rises to the appropriate level. Replace the cap and go about your business. In a day or two, recheck the level to be sure you don't need to add any more. So ...

Always clean the area around the cap.
Add brake fluid slowly.
Recheck in a few days.
One more thing:

Never shake a bottle of brake fluid before you add it to your car. The little bubbles can cause big problems