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Not all of our car care tips are about stuff we sell. This time I will go over some car care tips that will help you keep your brake system AND yourself tuned up for winter, and all year round. Winter and ABS, they are made for each other! Almost all cars built since about 1986 or so have ABS (Anti-lock Brake System and NOT the Australian Bureau of Sheep which comes up near the top if you just search Google for ABS). How ABS works ABS consists of sensors at the wheels and brake lines to all wheels that are routed through the ABS pump. Some systems are three channel where the two front wheels are controlled independently and the two rear wheels are plumbed together. Four channel ABS has separate control of all four wheels and is what most cars built since about 1990 have. ABS systems are pretty tough and foolproof, but things can go wrong. Wiring to sensors can be damaged, as can the ring that the sensor uses to detect wheel movement. If you look at your wheels and behind them, you can sometimes see the ring attached to the hub. This turns with the tire/wheel. it sometimes looks like a gear with square teeth and sometimes as a ring with holes in it. The sensor, usually mounted to the brake attaching hardware, uses a magnetic sensor to detect when there is metal near it and when there isn't (the gaps or holes in the ring). When the computer connected to the sensors detects that one or more of the wheels is going slower than the others, it cuts brake line pressure to the wheels going slower. It does this several times a second. If you got proper drivers training, especially before ABS was common, you were taught to "threshold brake" by applying pressure till you felt the car slide, then release pressure till the tires rolled again, then apply the brakes. The ABS does this same thing, but several times a second, a speed that the human brain/leg muscle combination can never match. Advantages of ABS ABS will, under most conditions, allow you to steer your vehicle while braking in what would usually be a skid. Without ABS, if you lock up the wheels, the tires have almost zero traction, and when you turn the steering wheel, the car still goes straight. ABS will allow under some conditions for the car to stop shorter than without. But for the most part, it won't significantly shorten stopping distances. Disadvantages of ABS Under some conditions like ice, packed snow, gravel, etc, ABS can actually lengthen stopping distances where a locked tire would build up more debris in front of the tire and stop quicker than if the tire rolls some. Another disadvantage is that most people never use the ABS because they never practice. How to get used to ABS As I write this, it is January in Illinois. There is fresh snow, about 1" on top of a layer of soft ice (ice formed right near 32 degrees, and thus not as hard as if it had turned colder after the ice formed). This is perfect for ABS training. What is ABS training? It is getting used to using ABS the right way. Chances are you got a video tape (or DVD) with your new vehicle that dealt with ABS, at least many vehicles did when ABS was still fairly new technology. But most people never watch it or read the owners manual. I can't blame people for not reading the owners manual when it is filled with obvious cautions like "Don't drive your car over a cliff, this can be harmful to you and void your warranty". OK, I never read that, but I swear 2/3 of any new product owners manual/instructions are filled with stupid cautions that are a result of our country having more law suits per capita than any other! The ABS training that I have used with my family consists of the first really good snow day. Find a safe place where you can get up to about 15-20 mph and slam on the brakes without anyone noticing or caring or getting in your way. A long private paved driveway is perfect, or a deserted parking lot with no light poles, curbs or other vehicles/people around. Get your car up to 15-20 mph and with the wheels straight, slam on the brakes....HARD. ABS works best when you jam on the brake pedal as hard and fast as you can. Trust me you won't break the pedal or mechanism, it is designed for this. Be prepared for a surprise. If you have never applied ABS, you will be surprised at the vibration in the brake pedal and usually the growling noise the car makes. This is NORMAL. ABS makes noise and shakes the brake pedal. That is to let you know it is working. The only thing is most people never experience this till it is too late. Sometimes never if you practice threshold braking like many of us do. We have to learn how to brake all over again. ABS will come on rather easily in snow/ice, but on dry pavement, it takes all you can give the brake pedal to make the tires skid sometimes. So doing the test in snow allows you to do it at a slower speed, and with almost zero wear/tear to the car and tires. The REAL safety feature of ABS Next, you should practice trying to turn while you apply the brakes. Slam on those brakes and then gently turn the wheel. You should notice that the car will turn. Without ABS, you would just go straight. ABS allows you to steer around obstacles while at maximum braking. You should practice this several times. Another good reason to play with your ABS in the snow ABS is like the muscles in your body. Use it or loose it. OK, that may be a little harsh, but ABS can develop problems without your knowing it. If a wire breaks then there is an ABS light that comes on, but if the pump clogs up from never being used, then the alert mechanism won't know it. By trying out the ABS several times during at least one time a year, you keep it from freezing up from disuse. Also, by using the system, you get brake fluid mixed up around the pump that normally just sits. Bleeding brakes with ABS is different than non-ABS systems Without ABS, when you bleed the brakes (flush the system brake fluid by pumping it out at each corner of the vehicle), you get all of it. With ABS, the normal operation bypasses the ABS pumps, and when you bleed or flush the system, you don't get it all. That is why most well-supplied repair shops and factory repair shops have a special tool to activate the ABS pump when bleeding the system. It is a good idea to have your brakes bled by a qualified service technician at least every two years. The fresh fluid prevents rust and contamination from destroying the master cylinder and brake caliper/wheel cylinders and causing leaks. Also brake fluid absorbs moisture from the air (why you should always use an unopened can of brake fluid when you add new fluid or flush a system. If you wind up with a partical can, discard it safely rather than keep it because the cap can't keep moisture from getting into the fluid once the seal is broken. Use the brake fluid specified by your vehicle's manufacturer. Or a fluid that meets those specifications. The same goes for Anti-freeze and Power Steering Fluid and automatic or manual transmission fluids. Drain/flush and fill with fresh fluids every two years at least. This is cheap insurance for any car you plan on keeping more than two years. To review: 1.
Maintain your brake system with a flush/fill every two years. Final tip to avoid rip-offs The auto repair business is littered with rip-off artists and scammers. The oldest trick is where the mechanic putting on new tires or doing an oil change points out to the owner that your brake pads are worn. They point to the pads and say they should be thicker! Understand that most NEW disk brake pads have a thickness of about 3/8" Most new break shoes have a thickness of about 1/4" This isn't much, and mechanics take advantage of this to try to convince people that your brakes need work. I once had a service shop putting on new tires try to do this to me. The "mechanic" called me to the front of my car and said my brake pads were dangerously thin. The thing is that the DAY BEFORE I had a reputable shop put new brakes on my car and they were still dust and dirt free and in perfect shape. I called the shop manager to my car, pointed out what had just happened and the mechanic was fired, as he should have been. So be aware of how your brakes are supposed to look and don't let shady mechanics cause you to spend money that isn't necessary.
Don Mallinson, President |
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