The last thing drivers want to realize too late is that their brakes are not working, which is why it's a good idea to check their performance every so often. With the holidays just around the corner and millions of Americans planning to drive to their destination, it may be good idea to check brakes sooner rather than later.

What you may not realize is most cars and trucks have vacuum-assisted power brakes. When you're driving and you notice that you have to press down harder than usual on the pedal, it may mean that you have a problem with the brake booster. Although your brakes are still working, a broken booster requires you to put a lot more effort into slowing down your car.

In order to check the booster, you should pump the brakes while your car's engine is off. You'll know when to stop when the pedal feels firmer and you don't hear any sound from the booster. Once you've pumped enough, turn on the car's engine. If you feel the pedal depress slightly, then your car is fine. If there's no change then the vacuum hose that connects to the booster may either be blocked or a bit loose. If the hose is working properly then the problem lies in the booster itself.

While this type is not as common, Hydro-Boost power brakes use hydraulic pressure from the steering pump as opposed to the vacuum system. In order to test this, pump your brakes five or six times while your engine is off before pressing down hard and starting the engine. Just like the vacuum test, a functioning brake booster will cause the pedal to fall slightly when the engine starts before rising again. Problems with this system could be caused by a worn power steering pump, leaks inside the unit or hose connection issues.

Although your brakes will still work, the extra pressure needed to get the car to slow down can be a major issue, particularly if you have to brake quickly due to someone suddenly stopping in front of you or an object in the middle of the road. Drivers should try the brake booster test before they take any long trips, leaving time to get the car repaired if need be.