The braking system serves as the lifeline for a truck’s safe operation, while brake pads act as the core components that directly determine braking performance. With every heavy-haul journey and every long downhill descent, brake pads are subjected to the rigorous trials of extreme heat, high pressure, and continuous wear.
Issues such as excessive wear, cracking, or uneven wear can—at critical moments—cause braking distances to lengthen significantly, or even lead to complete brake failure. For this very reason, mastering the skills to self-inspect brake pads has become an essential safety competency for every truck driver.
1. Look — Visual Inspection
Using a flashlight and an inspection mirror, observe the remaining thickness of the brake pads through the gaps in the wheel spokes. Generally, replacement is recommended if the thickness falls below 5 millimeters.
At the same time, check whether the wear is even on both sides; if excessive wear is observed on only one side, it may indicate a caliper return issue or a seized guide pin, requiring further inspection and repair.
2. Listening — Identifying Abnormal Noises
If a continuous, high-pitched metallic squeal is heard during braking, it typically indicates that the wear indicator tab (warning shim) has made contact with the brake disc, signaling that the pad thickness has reached its minimum limit and requires immediate attention.
If this is accompanied by a “clunking” sound or other periodic noises, it may point to issues regarding the flatness of the brake disc or problems with its installation.
3. Touch — Temperature and Condition Assessment
After driving and while ensuring safety, carefully touch the brake discs to check their temperature (taking precautions to avoid burns). If the temperature of a specific wheel is abnormally high, it may indicate that the corresponding brake pad is dragging or failing to retract properly.
Concurrently, inspect the surface of the brake discs; if distinct grooves, cracks, or localized blue discoloration (a sign of overheating) are visible, both the brake pads and the discs must be inspected and serviced simultaneously.
4. Sensory Feedback: Driving Monitoring
Pay close attention to the feel of the brakes during daily driving:
(1) If the brake pedal feels “mushy” or its travel distance increases, this may indicate excessive wear on the brake pads or the presence of air within the braking system.
(2) If the steering wheel or vehicle body shakes during braking, this is often linked to uneven wear of the brake pads or deformation of the brake discs;
(3) If the vehicle pulls to one side while braking, be alert to the possibility of a brake pad failure on one side or a malfunctioning brake caliper.
Additional Details to Note During Self-Inspection
Brake pads made of different materials—such as semi-metallic, ceramic, or low-metallic compounds—exhibit distinct friction characteristics and lifespans; therefore, they should be selected judiciously based on the vehicle’s specific operating conditions.
When inspecting brake pads, it is imperative to simultaneously examine the condition of the brake discs, as the two components function as a collaborative “pair.” While the dashboard warning system serves as a useful auxiliary tool, it cannot fully replace regular manual inspections; mechanical verification remains the more reliable method.
