Brakes are the most important safety feature for every single vehicle on the road. Yet for a semi truck with a heavy load in tow, the importance of well-tuned brakes holds even more importance. If even a single brake ceases to work the way it should, your vehicle may be at risk of losing control.
One of the most commonly experienced brake problems has to do with balance — in other words, some of your brakes doing more work than others. Don’t make the mistake of writing off this issue as no big deal. Over time, even a relatively minor imbalance will grow worse, putting you at greater and greater risk as it does.
Imbalance can be tricky to deal with, thanks to the fact that it may be caused by a wide variety of issues. If you would like to improve your knowledge of some of the factors that can play into braking imbalance, please keep reading. This article outlines three common sources of brake imbalance, and what an experienced technician can do to alleviate each one.
1. Glazed Brake Drum
A large proportion of trucks on the road today utilize drum brakes to provide their stopping power. When you press down on your brake pedal, your wheel cylinder forces a pair of brake shoes away from each other. These shoes contact the inner walls of the drum. The friction generated in this manner effectively brings your vehicle to a stop.
Yet a drum brake may not be able to generate the necessary level of friction if it suffers from the problem known as glazing. Glazing involves the surface of the drum becoming excessively smooth. This smoothness makes it difficult for the brake shoes to slow the drum’s rotation. As a result, glazed drums demonstrate markedly decreased stopping power.
Glazing often stems from overheating. Such overheating may occur during periods of prolonged or especially heavy use — for instance, when descending a particularly steep hill. Fortunately, technicians can often roughen up a glazed brake drum, thus making it easier for your brake shoes to generate the friction needed to slow down.
2. Mismatched Air Hoses
Whereas most passenger vehicles use hydraulic systems to power their brakes, trucks more commonly use air systems. Manufacturers consider air brakes a safer option because they can continue to work even if the system experiences a leak. In addition, mechanics have an easier time working with air brake systems, since the components can be detached without first draining the fluid.
In order to provide effective, well-balanced braking, however, an air brake system must be correctly managed. As components age, they often have to be replaced — especially the hoses, which can easily accrue damage. Many cases of imbalance stem from air hoses that do not meet the system’s specifications.
If a hose leading to a particular brake is smaller or larger than the hoses leading to the other brakes, it’s performance will not match theirs. For this reason, replacement hoses should always be selected and installed by a trained professional.
3. Malfunctioning Slack Adjuster
Over time, the surfaces of your brake drum and brake shoes wear away from friction. This loss of material changes the distance that the brake shoe has to travel to contact the drum. Every brake on a truck contains a component known as the slack adjuster. As its name implies, the slack adjuster compensates for wear in order to ensure proper brake contact.
Yet if a slack adjuster stops working properly, the related brake may cease to deliver correct results. Usually bad slack adjusters cause a lack of braking force. To resolve this source of imbalance, a technician must either repair or replace the slack adjuster in question.
If you believe that your truck may be suffering from an imbalance, you should seek professional assistance as soon as possible. For more information on what could be causing your problem, please contact the experienced pros at Godfrey Brake Service.