A car's brake fluid should be changed every 30,000 miles. Fill up an auto brake fluid reservoir with tips from an automotive service excellence (ASE)-certified master auto technician in this free video on automotive maintenance.
This is Dave Erb from Dave's Ultimate Automotive in Austin and we're going to be talking about checking and adding brake fluid. The brake fluid reservoir will have some markings on the side to indicate the minimum and maximum level. You want to go ahead and pull the cap off and don't just trust the side. You want to look down inside and see the fluid. Sometimes over time the fluid becoming dark will stain the reservoir. It may look like it has fluid in it or that the level is proper but when you look down in it you will notice that the fluid is low. The reasons brake fluid can get low are the brakes wearing and that fluid having to take up the slack left behind by pads wearing and caliper pistons having to be pushed out or you might have a leak somewhere. Brake fluid does absorb moisture which becomes acidic over time and eats away at the internal components of your brake hydraulic system. That's why it does need to be changed periodically. Every 30,000 miles is a good mark to think of. When you do have to add brake fluid all you really want to do is pull the cap off, see where your level is, get your fluid and make sure that you use the proper fluid for your vehicle. Some higher end vehicles do use higher end fluid, Dot 4 and above. Dot 3 is the most common and it should say it on the reservoir or on the cap. It will tell you exactly what you need. You just want to open your brake fluid and if you have got a steady hand you don't need a funnel, just add a little bit at a time until you get up to the proper level and it should be fine. This is also the most common reason for the brake light coming on your dash. If it does get a little low it does have a sensor on the side to let you know it is getting low and that's the point you would check it as well. But you want to go ahead and check it pretty much every oil change. That's checking and adding brake fluid.