If your brake pedal has started to feel a little bit soft or spongy under your feet, it's a key indication that there's a problem with your brake lines. It can be caused by air in the brake lines or low brake fluid. In some cases, it can also be the result of degraded fluid that needs to be flushed and replaced. If you've never looked under the cover of your master cylinder, here are the basics you need to know about checking and bleeding your brakes.
- Find the Master Cylinder – The first thing you need to do is look at your brake fluid's reservoir, or master cylinder, under the hood of the car. In most vehicles, the master cylinder is located on the driver's side of the engine compartment and is situated against the firewall by the passenger compartment. It is positioned here so that it's easier to connect the master cylinder to the brake pedal and the rest of the brake system. Most newer model cars are equipped with a master cylinder that's made of translucent material so that you can see the fluid inside at a glance. The master cylinders in older models are usually made of metal, so you'll have to remove the cap. It's usually secured in place with a clamp. Use a flat-bladed screwdriver to lift the clamp so you can remove the cap.
- Examine the Fluid – Check both the level of the fluid and the condition. There should be enough fluid in the reservoir to reach the "FULL" line. If it's low, that means not only do you need to add fluid, but you've got a leak somewhere. Add enough fluid to reach the "FULL" level and replace the top on the master cylinder. A brake mechanic can help you trace the path of the brake lines to spot any potential leaks. You may have a perforated brake line, or the leak could be around one of the gaskets or connections from the master cylinder to the brake assemblies. Look for any moisture around the brake lines as a key indication that the line is leaking. Look at the color of the fluid while you're there. It should be bright and somewhat translucent. If it looks cloudy, dark, or full of debris, it needs to be flushed and changed. Additionally, you'll want to have your brake mechanic evaluate your brake lines for any signs of damage.
The more you know about what to look for when your brakes don't feel right, the better your chances are of catching a problem before it leads to brake failure. Talk with your auto repair shop about your brakes if you have any concerns.