Brake fluid is required to ensure that your braking system functions properly. Brake fluid is an oily substance amber in color that lubricates the brakes on your vehicle. It is engineered to withstand a wide range of temperatures and is stored in a reservoir fastened on top of your car's master brake cylinder. Brake fluid is hygroscopic, which simply means that it absorbs moisture from the air. Moisture getting into your brake fluid is bad for a variety of reasons. The presence of moisture dilutes the brake fluid and lowers its boiling point, it contributes to the break down of the fluid, and it can lead to the rusting of vital brake parts or expensive auto repairs.
Brake Fluid Ratings and Classifications
Brake fluid, much like engine oil, comes in multiple classifications. The United States Department of Transportation sets the classifications for brake fluid, of which there are three: DOT-3, DOT-4, and DOT-5. These types of brake fluids are not interchangeable. ABS brakes for example cannot use DOT-5 brake fluid. What differentiates the three types of brake fluid is their boiling points. Because brake fluid is subjected to engine heat at extremely high temperatures, it must have a high boiling point to ensure that it does not get vaporized. The type of brake fluid your vehicle uses will be disclosed in the owner's manual. Most passenger cars use DOT-3, but do check the car manual to be sure.
You Can Easily Add Brake Fluid via the Brake Fluid Reservoir
Check Brake Fluid
You should check brake fluid every 3,000 miles or as directed by your car manual. It may help you to remember to check the brake fluid if you do it every time you change your oil. If your brakes start to feel a little less responsive or spongy, you should check the brake fluid as well.
Checking brake fluid is simple enough for any car owner to do. Start by parking your car on flat, level ground. Under the hood, locate the master brake cylinder, which you can usually find toward the rear of the engine. The brake fluid reservoir will have a cap on top that will read Brake Fluid and display the fluid rating as well, e.g., DOT-3. The brake fluid reservoir will be translucent with markings on the side. The markings are clearly labeled, typically using Full and Add or Max and Min to indicate whether adding brake fluid is necessary. Because the brake fluid reservoir has markings on the side rather than a dipstick you will have to judge by eye whether more fluid should be added. Do not just look at the level, however. Also examine the brake fluid color and appearance. Fresh brake fluid is amber colored and it darkens over time. If your fluid looks very dark and discolored, cloudy from water contamination, or if you notice bits of metal swimming in it, then you should have a brake fluid flush done.
Signs of a Brake Fluid Leak
If your brake fluid level is significantly low, it may be the sign of a brake fluid leak. Examine the master cylinder and brake line connections underneath. Check the brake lines for cracks. If you notice any dark fluid drips or pools underneath your car it may be brake fluid. If it is near your tires and brownish, you may have a brake cylinder leak. If you discover any leaks or if the brake warning light on your dash is illuminated, your brake system needs immediate attention.
Adding Brake Fluid
Adding brake fluid should not be something that you have to do often. Having to add brake fluid can be a sign of a larger problem, but if you do not detect any brake fluid leaks, your brake system warning light is not lit up, and your disc brake pads are not over worn, you can add brake fluid to keep your brakes in safe working order. There are a few important things you should be aware of before adding brake fluid to your car. Because brake fluid absorbs moisture from the air, opened bottles of brake fluid attract moisture. So always start with a brand new, sealed bottle and do not store any left over. Be especially careful not to spill any brake fluid on your car as it will eat the paint right up causing bubbles and peeling. In addition to moisture, dirt and debris can harm brake fluid as well. So make sure you thoroughly clean around the reservoir cap and the cap itself with a lint free rag to keep any dirt out.
How to Add Brake Fluid to Your Car
Turn the brake fluid reservoir cap counterclockwise to remove it. Place the cap somewhere it will not get in the way or fall to the ground and get dirty. Open your brake fluid bottle, remove the foil seal completely, and throw the seal out. Insert a clean funnel into the reservoir. Use a new funnel if possible and do not use a funnel that has been used previously for any other purpose to avoid contamination. Slowly pour the appropriate amount of fluid into the reservoir, being careful not to over fill. Remove the funnel, wipe down the reservoir cap and replace it snugly. If you have added brake fluid, you will want to check the level after your next drive or in 10 to 20 miles or so. Have your brakes serviced as soon as possible if you notice a drop in the brake fluid level.
Brake Fluid
Your brakes are obviously an important safety feature of your car. Aside from the obvious screeching and squealing that can be a clear indication of a brake problem, a low brake fluid level may also be a warning sign. Most drivers, however, rarely if ever check their brake fluid level. Luckily, checking the brake fluid is easy and if you need to add brake fluid that is very doable as well even if you otherwise know very little about cars. This one little maintenance check can save you from an expensive or dangerous surprise somewhere down the line.
