Seven horseshoe nails

Negligence of simple preventive maintenance checks can have a domino effect that results in three large expenses: a road service call, unplanned downtime and a repair that might have been avoided.

It’s a classic proverb, more than a century old when Benjamin Franklin passed it along in 1758: For the lack of a nail, the horseshoe is lost, the horse is lost, the rider is lost, the battle is lost, the kingdom is lost – “all for the want of a nail,” as it’s often repeated.

Owner-operators lose the battle against unnecessary expenses and wasted time in much the same way. Breakdowns requiring road service consume hours, cost hundreds of dollars and exact a human toll of frustration and anger. But most of them can be prevented by simple checks of the most basic things, such as air pressure, drive belts and fluid levels – in short, the basic horseshoe nails, most often learned from dad or in truck-driving school.

“The guys who take care of their trucks don’t have breakdowns,” says Mike Peterson, owner of Prairie Truck and Tractor in Devil’s Lake, N.D. “But a lot of drivers don’t even look at the truck. They just drive.”

Breakdowns often follow a general pattern, road-service pros say: “One little thing goes wrong, and it makes other things go wrong,” says Brian Telford, owner of this site. “You can have something like a hose clamp go bad, and that’s stupid. But then the road service guy doesn’t have the right part, or he doesn’t have enough antifreeze, and something really simple winds up being a $700 repair.”

Telford offers another example: “A guy doesn’t check the air in his tires properly, and one tire explodes and makes the other one explode and blows the mud flap off.”

If a vehicle has problems, severe temperatures often reveal them.

“Extreme heat and cold cause breakdowns constantly,” says Tom Prash, national sales manager for Truck Tire Service in Chelsea, Mass. “If it’s hot, tires blow more often. If it’s cold, we have more engine failures. Bottom line: When it’s very hot or very cold, our business increases dramatically.”

Here are seven of the most common causes of breakdowns that often require road service.

    Failure to regularly check air pressure is a sure path to problems. If a tire is low on air, the sidewalls bulge, the steel cords flex too much and can break. In some cases, the tire explodes. Even a little extra sidewall flexing will dramatically shorten a tire’s life, rule out retreads and make a blowout more likely.

    At the other extreme, if pressure is too high, as the tire warms from use and the air expands, the tire can explode.

    Air pressure in most steer tires is 110 pounds per square inch, and most drive and trailer tires are at 100 psi. Some owner-operators keep trailer tandems at 80 psi, drives at 90 and steers at 100. Others fill drives to 110 and steers to 120.

    Another problem is what Prash calls driver abuse. “They run over curbs and damage tires,” he says. “Overloading vehicles causes tire problems, too,” whether the maximum load is 80,000 or 250,000 pounds.


    • Check air pressure daily or whenever you hook to a trailer.
    • Keep any variance from the recommended pressure, listed on each tire’s sidewall, within 2 psi. Before significantly over- or under-inflating tires, check with the manufacturer’s rep about warranties and potential problems.
    • Check tread depth daily. Federal Motor Carrier Safety Regulations mandate steer-tire tread at a minimum 4⁄32 of an inch and drives and trailer tandems at a minimum 2⁄32.
    • Know your tires’ maximum load capacities and stick to them.
    • If you frequently run over curbs on turns, train yourself not to, or get a friend’s help in improving your steering skills.
    Problems with electronics and wiring are becoming more common on newer trucks, Peterson says. “Some of it a guy can watch for: loose connections and hanging wires,” he says. “But some of them go suddenly.”

    He says such problems get more likely as the truck ages. “They have more wiring and sensors, and all of that is subject to road vibrations and heat, and pretty soon you have trouble.”


    • Inspect the wire connections on electronic components and replace any that are loose, corroded or frayed.
    • After driving in winter cold, salty air or mud, rinse corrosives and dirt off connectors with WD-40, which also is a good conductor.
    • Make sure wires are protected and not touching or rubbing against hot surfaces or sharp edges.
    • Make sure electrical/electronic components are tightly secured.
    • During maintenance, ask the mechanic if any wiring is old and needs replacing.
    • If electrical components start acting strange, check the connectors immediately.
    • Keep spares on hand of each small component.
    Neglecting the compressor can lead to loss of air pressure. “Compressor problems usually creep up on you,” Telford says. “You get a warning from the dash gauge and have time to do something about it.”

    Most often, however, air pressure problems are elsewhere, usually a valve on the trailer or truck, Telford says. Leaky connections also are common. Although air hoses and lines are tough and built to take punishment, they can be damaged.


    • Be thorough with pre-trip and post-trip inspections of hoses.
    • Listen for high-pressure leaks, audible even with the engine on. If a hissing sound persists, don’t drive until you’ve stopped the leak.
    • Investigate any automatic warnings about the compressor. Don’t wait.
    Temperature extremes are the enemies of these simple parts. A belt installed in cold weather might expand and be too loose when it warms up. A belt installed in warm weather might contract and snap in cooler weather.

    Radical temperature differences in a short time period play havoc with neglected belts, hoses and clamps. Run from the Southwest into Canada on certain spring or fall days, and the change could easily produce leaks if hose clamps aren’t tight.


    • Closely inspect hoses, belts and clamps weekly and during extreme temperature changes.
    • If necessary, ask an expert to explain proper belt tension and how to spot weak hoses.
    • Replace bulging or cracked hoses.
    • Make sure clamps are tight. Replace if weakened from corrosion or wear.
    • Check belts for tightness. Replace if cracked, torn or frayed.
    • Carry spares of each belt, hose and clamp.
    A brake problem might not force you to the shoulder, but an inspector’s verdict on your brakes can do just that. And, of course, brake failure causes wrecks that are far worse than being sidelined.

    “Last year, the number one item for out-of-service violations, 29 percent, was brake adjustments,” says Stephen Keppler of the Commercial Vehicle Safety Alliance. “The next item, 27 percent, was for braking system component issues: a bad lining or a broken brake-line air hose.”

    Federal regulations mandate brake specifications. For example, air disc brakes must have 1⁄16 of an inch of lining; air drum brakes must have 1⁄4 of an inch. The regs also specify play in slack adjusters.

    A common brake problem on older trucks and trailers is “the spring inside the brake chamber snaps,” Telford says. “That’s a difficult one, because the driver can’t see it happening. The spring breaks, the brakes are applied, and the truck won’t move.”


    • During preventive maintenance on older vehicles, have a certified mechanic check brake chamber springs. This requires special tools and training, and it’s highly dangerous.
    • Check slack adjusters during each preventive maintenance, when you swap trailers, before driving in mountains and when you’re not sure they’re legal
    • Wearing gloves, grab and pull hard on each slack. If any move more than an inch, locate and tighten the 3⁄8-inch adjusting screw until movement is less than an inch.
    • If you’re not comfortable working on your brakes, let a mechanic set your slack adjusters and check your linings. The labor fee is a lot less than the road-service fee, or the costs associated with being put out of service.
    • During pre- and post-trip inspections, check your brake system for leaks. Make sure low-air alarms and the compressor work properly. Fix leaks before driving.
    • Make sure trailer brake hoses are at least a foot off the ground.
    Running lights and electrical appliances with the engine off might not drain your batteries all at once, but constant drains eventually kill them. Sooner or later, that will happen in a situation that requires road service.

    Idling is not the answer. That only wastes money, wears out your equipment, pollutes the air and invites a hefty fine in the many jurisdictions that now restrict the practice.


    • Invest in an auxiliary power unit. APUs have their own batteries independent of the truck’s electrical system. They also have low-voltage disconnects.
    • If you run a lot in the North, get an in-cab auxiliary heater. It can pay for itself in as little as a year.
    • Use a shore-power hookup, available at increasing numbers of truck stops and terminals nationwide.
    • Get in the habit of using less power when parked. A bag of ice, for example, may keep your fridge plenty cool overnight. Simply cracking the windows and running a battery-operated bunk fan may beat air conditioning on many days. In winter, a heavy comforter or sleeping bag can work wonders.
    Take big trucks off the pavement, and it doesn’t take much to hang them up, especially in winter.

    “It’s the mud and the snow,” Telford says. “They’re trying to get into or out of a customer’s lot, or they sleep on the side of the road, and when they wake up they can’t get out.”

    In any weather, deep potholes or a leaning trailer can tilt the truck, put the drives in thin air and hang you up. That’s why empty trucks, or trucks with loads weighing under 30,000 pounds, are more likely to get stuck.


    • Stay on pavement or hard-packed, graded dirt roads. When in doubt, get out and check the surface. If walking on it is difficult, driving or parking on it will be worse.
    • If a shipper or receiver has a poorly maintained lot, politely explain the problem to whoever’s in charge, or to your dispatcher.
    • Know your route and plan where you’ll stop when you’re out of hours.
    • Know the weather report for your whole route, including any highway alerts, and plan accordingly.
    • Keep a tow chain in your truck; a truck with good traction usually can pull you free. Make sure the chain can handle the weight, and have at least 100 feet so you can double it.
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