Safety Updated 3 min read
A change in braking performance needs prompt attention. If stopping ability is reduced, air pressure is unsafe, or the vehicle displays a stop instruction, stop safely and follow the operator manual and your fleet's response procedure. Do not continue driving or attempt a road test to decide how serious it is.
Report Changes in Performance
Describe what changed: longer stopping distance, pulling during braking, delayed release, or a different pedal response. Record whether the concern began suddenly and whether the truck was coupled to a particular trailer. These observations help define the complaint; they do not establish which brake or component failed.
A pull or vibration can involve more than one system. Avoid assigning a side or ordering parts based only on what the driver feels. A physical inspection and appropriate tests are needed before a repair decision.
Keep Air-System Symptoms Separate
For air-braked equipment, report low-air warnings, abnormal gauge behavior, slow pressure recovery, or a new audible leak. Note whether the symptom appears while parked, during brake application, or after a trailer connection. Use the manufacturer's instructions and required driver checks; this article is not an air-brake test procedure.
Do not work on pressurized brake components or adjust a system to hide a symptom. Repair and adjustment require the right training and procedures. Tell the technician if any previous adjustment or repair was made.
Understand an ABS Warning
An ABS lamp reports information about the anti-lock system. It is different from a driver's report of poor service-brake performance, although both concerns may be present. Record the exact lamp or message, whether it stays on, and whether it appears on the tractor, trailer, or both.
Do not assume an ABS warning proves a wheel-speed sensor needs replacement. Wiring, connections, sensor signals, power supply, and other components may require testing. Our ABS diagnostic service starts with the warning and the equipment configuration.
Note Noise, Heat, and Visible Damage
Grinding, smoke, a burning smell, damaged hoses, or visible loose or broken parts need assessment. Stop safely when there is an immediate hazard. Never touch a suspected hot wheel end or reach under unsecured equipment to investigate. Describe where the sign appeared and provide photos only if they can be taken safely.
Prepare a Useful Service Report
- Identify the tractor and trailer, not just the driver's vehicle number.
- Describe the first symptom and any warnings in the order they appeared.
- Record the load condition and approximate location or operating conditions.
- Include recent brake, tire, wheel-end, or suspension work.
- State where the equipment is parked and who can coordinate recovery or approval.
Keep Inspection and Repair Records Connected
Required inspections do not eliminate the need to respond to defects between inspections. FMCSA's maintenance guidance explains the broader inspection and repair responsibilities for regulated operations. Follow the requirements that apply to your vehicle and operation.
Big Rig Fixer offers air brake repair and trailer service. Call with the symptoms before moving equipment when safe transportation is uncertain.