Truck Brakes Aren’t as Fragile as You Think They are

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man near a red truck

“The truck lost its brakes.” This is the most common reason we hear of truck accidents. It leads many motorists to assume that the big vehicle’s brakes are untrustworthy. What with the devastation a 16-wheeler can cause, we can’t really blame pedestrians and other drivers for fearing trucks.

But if you’re a mechanic, or simply a car enthusiast, you’d know that brakes don’t just snap easily, much less if it’s a truck’s. Reliable long-haul transportation, after all, is designed to withstand heavy cargo and long-distance drives. As such, its brakes are secure. So if that’s the case, why do so many truck brakes fail?

The Truth About Brake Failure

In many truck accidents with brake failure as the cited reason, the telltale skid marks are rarely found by investigators. But that evidence can also prove that the driver has failed to step on the brakes. This failure becomes more common during the holidays when the highways are congested. More accidents happen when traffic flow is slow. Since regular highway users aren’t used to low speeds, they become impatient and make up for the lost time by driving faster. And if you’re driving a truck, speeding can result in catastrophic accidents.

Truck drivers who are used to slower drives may also fail to hit the brakes. In a highway, like the North Luzon Expressway or SCTEX (Subic-Clark-Tarlac Expressway), for example, they may not practice a quick brake response. They also aren’t used to applying a stronger force on the brake pedals. If they brake too late, and they avoid their bumpers from getting hit, there’s no guarantee that the vehicle behind them will engage their brakes on time. That’s what causes nose-to-tail chain collisions.

Therefore, so-called brake failures are all but human error in most cases. For truck drivers unused to fast brake responses, stepping on the pedals with stronger force is uncharted territory. But that’s not a valid excuse for speeding or causing a collision. Professional drivers must practice defensive driving, which means anticipating risks before they become imminent. If their instincts tell them to step on the brakes with more force than they’re used to, they shouldn’t hesitate.

truck components

Brakes Can Malfunction, But Not Fail

Throwing around the word “brake failure” carelessly is what makes non-truck drivers wary of the big vehicle. To say that the brakes have failed is actually an inaccurate description of a brake problem. Yes, brakes can stop working normally or heat up, but they never fail, at least not by themselves.

If an interruption occurs in a truck’s air supply, the spring brakes would engage. This provides a stopping force equivalent to around 60 PSI (pounds per square inch) brake application. That’s enough force to stop the truck under normal conditions, assuming that the brakes are working normally.

If the brakes were applied longer than necessary, overheating may occur. The brakes’ condition will become less optimum as a result. The heat expands the brake drums, so the brake’s adjustments have to be extended past the maximum brake stroke length. And brakes stroking beyond their adjustment limit become less efficient, its stopping power decreasing.

In other cases, the automatic brake adjusters are manually adjusted too often, causing the mechanism to fail at maintaining proper adjustments. This type of brake malfunction was the possible reason for a collision between a dump truck and a four-passenger car in Pennsylvania in 2003. The accident is documented in the U.S. National Transportation Safety Board Report.

In that accident, investigators discovered that the dump truck’s mechanic had adjusted the automatic brake adjusters too many times. It caused the clutch mechanism to wear out, causing the automatic adjuster to “unadjust” each time the brakes were applied.

Considering that, the key to driving a truck safely is proper brake maintenance. Doing this will avoid human errors and make highways safer for all motorists.

Truck Brake Maintenance

During your regular preventive maintenance, inspect the air brake chamber housings. Look for signs of damage or corrosion, and address them immediately. Ensure that the dust plugs are securely installed and seated. Check for cuts and tears on the protective boots of air-disc-braked wheel-ends.

Inspect the air disc brake guide for possible slidability issues as well. The shear adapter cover should be in place and securely seated. If the truck is going to be driven in rainy weather, ensure that the automatic slack adjusters are adequately lubricated. That will prevent corrosion due to water exposure.

Thankfully, it doesn’t snow in the Philippines, so truck brakes here aren’t as prone to corrosion as those in four-season countries. But that’s not an excuse to skimp on maintenance. Your attention to the nitty-gritty bits will ensure that your truck stays in optimum condition, and won’t be a threat to other road users. A truck with trustworthy brakes, and a trustworthy driver, is good for your business and reputation.

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