The braking system of a truck is an embattled entity. Perhaps more than any other system, its foes are numerous and often difficult to contend with. But that doesn’t mean you have to throw in the shop rag and surrender. Use the tools your expertise and knowledge afford you to perform good brake jobs and educate drivers about how they can avert road peril to lengthen brake life, and you should set your customers up for smooth sailing-and seamless stopping.
The first step toward helping your customer get the most from his braking system is to know a braking system’s enemies. First, there are the uncontrollable factors that can stress a truck’s braking system, such as poor road conditions or erratic drivers. Over these occurrences, you have little control.
But there are other factors that cause premature brake wear that you can battle. One leading such factor is heat. A brake’s first job is to stop a vehicle, then control the heat that the stop generates.
Dennis Griffin, product manager, Abex Heavy-Duty Friction, Federal-Mogul Corp., said, “As brake temperatures rise, the wear rate of the friction material increases. Causes of excessive heat include duty-cycle, mismatched brake linings and component malfunction.”
If a truck operates in a severe-service environment, duty-cycle is a major obstacle to brake life. For example, brakes on stop-and-go applications, such as dump trucks and city vehicles, tend to wear faster because they don’t cool down between applications.
Make sure you match the correct brake lining to a vehicle’s service. For example, brake lining designed for an on-highway truck will wear at a much faster rate if it’s installed on a severe-service vehicle. It’s also necessary to have matching brake linings on the same truck.
“If you use different brake linings on a tandem axle, the lining with the best stopping power is going to wear faster because it will be doing more of the work. That’s why it’s important to replace all of the shoes on a tandem axle rather than just the axle that is experiencing more wear,” Griffin said.
Bad driving habits also can generate excessive heat. Warn your customers about the negative effects of aggressive driving at high speeds and quick braking habits. Although they may be trying to save precious time by reaching their destination faster, they will lose far more time in the long run if they prematurely wear out their brakes and must leave the road to undergo costly repairs and braking system replacements.
You also can talk to your customers about contamination, another frequent cause of early brake wear. Debris from the road can imbed itself in the brake shoe, generating rapid deterioration of the brake lining and drum.
Griffin recommended using dust shields to control the issue. Impart the importance of quality dust shields to your customers.
Though you might not be able to melt ice off roads, slow a speeding driver or remove debris from a highway, you can control the quality of the brake job you deliver. According to Griffin, “Performing a complete brake job-including a thorough inspection of all components-will go a long way toward eliminating premature wear.
“During a brake job, all brake system components need to be checked carefully to be sure they are fully operational. It’s important to install new brake hardware when replacing shoes,” Griffin said.
“Other key considerations when performing a brake job are brake balance (make sure the brakes are wearing evenly from side-to-side and front-to-back) and S-cam movement. Excessive S-cam movement can reduce braking effectiveness. If movement is more than .03″, replace the bushings and the seals,” he said.
Travis Hopkey, director of marketing, Phillips Industries, pointed to the air system as something that, if properly maintained, can the lives of the breaking system components. “Great care is taken to select the right brake and drum, but the air system itself often is forgotten. Use of a quick-release valve can go a long way in reducing brake costs.
“Even customers who know the benefits of quick-release valves many times are not placing them in the most optimal spot on the vehicle. Since brakes don’t release until all the air is out of the system, the valve needs to be in the best position to help the air escape,” Hopkey said.
He recommends installing a quick-release valve in the middle of the vehicle so the escaping air is released equally from the front and back.
While performing a brake job, use all your senses to examine not just the individual system parts, but the surrounding componentry as well. The experts Truck Parts & Service spoke with stressed the importance of never jumping to conclusions when addressing a braking system problem; explore all possible issues before undertaking a repair.
Also, talk to your customers about what part they can play in getting the most out of their brakes. You cannot always be the vehicle’s eyes and ears, but opening the lines of communication with your customers will go a long way toward combating premature brake wear.