Few things in your daily life are as dangerous as hurtling down the highway in a couple tons of steel, and the last thing that you want is for your brakes to give out, which can lead to dangerous or even fatal crashes. If you have a problem with your brakes, then you will want to fix it as soon as possible. To help you out, here is a guide on how to diagnose a problem with your brakes:
Test the Brakes at Rest
Find somewhere that is secluded and open so that you have plenty of room to maneuver and a minimal chance of hitting something. This way, if your brakes do end up failing, your car can coast to a safe stop.
First, put the car into neutral or park. Slowly depress the brake to determine exactly when the resistance kicks in. If everything is working properly, the brake should begin to push back before reaching halfway between resting position and the floor.
Apply an even pressure to the brake. If the brake holds in position, then you're good. However, if the brake slowly depresses to the floor, even though you aren't increasing the pressure, then you might have some air trapped in your brake lines.
Test the Brakes While Driving Slowly
Next, you will want to slowly drive around the area. If you have power brakes, test the brakes every so often to see how much force is required to actually stop. You should need to push the brake down between 1 and 2 inches from the floor. If they require more force than that, there might be a problem with your power booster. Since power brakes multiply the force you exert, unresponsive brakes might indicate that they are not functioning properly.
Pump the Brakes
Now you'll want to pump the brakes a few times. The brakes should end up in the same position that you started in. If they are higher, the problem might lie with your brake fluid. To confirm that, look for the master cylinder under your hood. The master cylinder holds hydraulic fluids and is used to distribute force throughout the car.
Fill your master cylinder and let your car rest for a few days or hours. Check your master cylinder once more to determine whether it is still full. If it isn't, then you might have a leak somewhere, which will probably require a trip to a professional auto shop, like Care Muffler & Brake Shop.