Why Do Truck Brakes Lock When Driving?

Brakes are some of the most crucial safety features for your truck. You need to do regular brake system maintenance. If they decide to lock up when you need them most, it can be very dangerous. Such a scenario can make some drivers to panic. Let us look at why truck brakes lock when driving and give you details of what you need to do when it happens.

Why Do Truck Brakes Lock When Driving?

Brake locking on your truck can be a result of several causes. The problem of brake lock boils down to two scenarios. First, it happens at that moment you least expected, and second, if you press hard the brakes at once. Below are some of the possible common causes of brake locks when driving. 


The Anti-Lock Braking System sometimes develops complications. If it happens, your brakes will lock up. Some trucks will show the ABS check light on the dashboard to signal the potential issue with the ABS. Never ignore this light whenever it appears. Instead, take your truck for a diagnostic to establish and fix the problem. 

When performing the diagnostic, some codes will be generated, which the technician will study to determine the actual problem with your ABS. 

The Brake Calipers

Sometimes, brake locks might not result from the ABS issues. Consider the brake calipers as another potential cause in such a scenario. For your brakes to function correctly, various components work together. The brake calipers squeeze the brake pads, making them cling to the brake rotors. Such action stops your truck. 

Three parts facilitate the movement of the brake calipers. The first part is the slide pins, which they move on. The hydraulic fluid is the second part, which generates pressure that pushes them, and finally, the caliper pistons.

Sometimes, the pins or the pistons can become warped or affected by the surrounding conditions. In such a scenario, your brakes will lock. In such situations, your mechanic will inspect and check the brake calipers’ state and their components. If they are faulty, your mechanic will consider replacing them. 

The Hydraulic System

The hydraulic brake system also causes the brakes to lock up. The hydraulic system is a significant component of the braking system. Whenever you press the brake pedals, the hydraulic fluid will be released and generate pressure, making the brake calipers clump the brake pads. When the brake pads are clamped, they will cause friction on the brake rotors, slowing or stopping your truck. 

The hydraulic fluids operate in tubes. If there is a breakage in the lines, it will not be able to generate adequate pressure and leak. Such instances will lead to brake lock up. If your technician realizes the hydraulic system has a problem, they will check the brake fluid first. If they find it low, they will check if the valves and the seals on the master cylinder are okay. They will also check for leaks in the lines. 


Most fatal accidents result from the problems of brakes locking up at the moment when the driver needs them most. If you find yourself in such an ugly situation, stay calm and consider the above reasons as the potential causes. 

Posts Tagged with… ,