5 Ways Your Car Is Trying To Kill You
Updated October 3, 2015
Brake fluid is hygroscopic, which means that it absorbs moisture. For the longest time I wondered why the Federal Government would set a standard that, over time, would reduce the effectiveness of the braking system. Then I learned the reason was that by trapping water in the brake fluid it wasn’t able to corrode the brake lines, which would make for a major problem. If you’ve taken a physics class you know that if you have a fluid in a pipe that whatever pressure you exert at one end will be the same as the force received at the other end. So where’s the problem? Brake systems, especially in hard use, can see temperatures of several hundred degrees, more than enough to boil the water trapped in the system. Since gas is compressible, it significantly reduces the effectiveness of your braking system, something you don’t want to learn when driving down a steep grade. The only answer is to follow your vehicle manufacturer’s recommended brake fluid system maintenance schedule.
Most brake pads installed on cars and light trucks these days come with a warning device that comes into play when the material in the brake pads is close to completely worn. It typically consists of a metal clip mounted to the side of the pad itself, and when the pad is worn sufficiently, the clip comes in contact with the brake rotor and makes a screeching sound. The problem is that most cars today have what’s referred to as sliding calipers, meaning that there’s a single piston on just one side. Sliding calipers , because of the uneven application of force they apply can create a condition called taper wear. Taper wear can result in a condition where part of the pad could be metal-to-metal, but the other part, where the clip may reside, still has pad material left. The result could be unrecognized, but extremely diminished, braking capabilities.
Tire Tread Depth
Most people believe that when they see the wear bars even across the tread of their tires it’s time to go the tire dealer and have them replaced. Well, that’s wrong. At the level of the wear bar (2/32″) your tires are considered completely worn and illegal to operate on public roads. The reason? A tire worn to 2/32″ will take twice as long to stop from 70 mph than a new tire. That could be the difference between stopping safely on a clogged freeway or ending up in the back seat of the car in front of you. And it gets worse. Even with a moderate amount of rain, the car with 2/32″ tires took FOUR TIMES as long to stop than the same car with new tires. What to do about this? I would imagine you know the Lincoln Penny tread check. Well now the recommended check is to use a Quarter and George Washington’s head for an extra margin of safety.
Tire Inflation Pressure
While modern radial tires offer many advantages over their predecessors, one negative aspect is that it’s very difficult, if not impossible, to be able to eyeball that a radial tire has a significantly reduced tire pressure. Survey after survey has confirmed that most Americans are driving around with their tire pressures below the vehicle manufacturer’s specification. And a percentage of those surveyed have tires that are dangerously underinflated. Tires are porous and lose air over time. Temperature changes and other circumstances effect pressures as well. So what happens when an underinflated tire overheats (due to excessive sidewall flex caused by underinflation) and fails? First, it’s not a benign failure. The tire actually explodes. If it’s on the steer (front) axle, a large degree of steering control is lost, and if you’re driving 80 mph and hit a concrete wall, sign post, another car, etc. the forces are FOUR TIMES as violent than the same crash at 65 mph (as force increases at the square of speed). So, two rule: One, keep your tires properly inflated, and Two, don’t hit anything.
There’s no dispute that airbags have probably saved more lives than any safety feature since the adoption of seat belts in automobiles. The problem is that air bags are powered by an explosive cartridge which generates a tremendous amount of force (not the soft-looking inflation you see in television comedies). According to the National Highway Traffic Safety Administration (NHTSA): “Advanced frontal air bags are a supplemental restraint system, just like earlier generation air bags, and must be used in combination with a seat belt. Occupants who are unbelted or seated too close to the frontal air bag module when the air bag deploys can be seriously injured or killed. No air bags – even advanced frontal air bags – can be designed to handle every situation. Air bags can still cause serious injury or death to occupants who are not properly restrained and in the proper seating position.”
Categories: Gear Grinding