Common Defective Parts in Commercial Trucks
Commercial trucks rely on thousands of individual components to operate safely at highway speeds. When any one of those parts fails, the results can be catastrophic for other drivers on the road. Federal Motor Carrier Safety Administration data consistently identifies specific categories of parts that fail most often in large truck crashes.
Brake systems account for the largest share of equipment failures in commercial truck accidents. An 18 wheeler traveling at 65 miles per hour needs roughly 525 feet to stop under normal conditions. A defective brake line, worn brake pad, or faulty air brake valve can double or triple that distance. Carriers operating on Interstate 20 and Interstate 49 through Shreveport share the road with thousands of passenger vehicles every day, making brake failures particularly dangerous in this corridor.
Tire defects are the second most common equipment failure. Tread separation, blowouts from manufacturing flaws, and improper load ratings all cause drivers to lose control. Steering system failures, including defective power steering pumps and tie rod ends, prevent a driver from correcting course. Coupling device defects between the cab and trailer can cause a trailer to separate entirely at speed. Defective lighting systems, including failed brake lights and turn signals, remove the warning other drivers depend on to react.
Each of these categories points to a different responsible party. The part manufacturer, the company that installed the part, or the carrier that failed to inspect it may all bear liability depending on the facts.
Louisiana Products Liability Act
Louisiana governs defective product claims through the Louisiana Products Liability Act (LPLA), codified at La. R.S. 9:2800.51 through 9:2800.59. This statute provides the exclusive remedy for damages caused by a product's defect. A claimant cannot pursue a separate negligence claim against a manufacturer outside of this framework.
Under La. R.S. 9:2800.54, a product is considered unreasonably dangerous in four ways. A construction or composition defect means the product deviated from its intended design during manufacturing. A design defect means an alternative design existed that would have prevented the damage and was economically feasible. An inadequate warning claim applies when the manufacturer failed to provide sufficient instructions about a known risk. An express warranty claim arises when the product failed to conform to a warranty made by the manufacturer.
The claimant must prove the product had a defect that made it unreasonably dangerous, the defect existed at the time it left the manufacturer's control, and the defect caused the damages. Louisiana courts apply a risk utility balancing test for design defect claims. The court weighs the likelihood of harm, the severity of that harm, the burden on the manufacturer to adopt an alternative design, and the effect that alternative would have on the product's utility.
For truck accidents occurring after July 1, 2024, the prescriptive period is two years from the date of the accident. For accidents before that date, the prescriptive period was one year under La. C.C. art. 3492. Missing this deadline permanently bars the claim regardless of its merit.
Manufacturer, Carrier, and Distributor Liability
Defective truck part cases often involve multiple defendants. The LPLA imposes liability on the manufacturer of the defective component. This includes the company that designed the part, the company that fabricated it, and any entity that placed it into the stream of commerce under its own name or brand.
The trucking carrier may also bear responsibility. Federal regulations under 49 CFR Part 396 require motor carriers to inspect, repair, and maintain all commercial vehicles under their control. A carrier that fails to perform required pre trip inspections or ignores known maintenance issues can be liable for negligence independent of any product defect. If a brake component showed visible wear during a required inspection and the carrier continued to operate the truck, the carrier shares fault alongside the manufacturer.
Distributors, parts suppliers, and maintenance shops may also face claims. A distributor that sold a part it knew or should have known was defective can be held liable under the LPLA. A maintenance shop that installed a part incorrectly or used a part not rated for the vehicle's specifications can be liable for negligence.
Louisiana's comparative fault system, which now applies a 51 percent bar to accidents occurring on or after January 1, 2026, allocates fault among all responsible parties including the injured person. If the injured person is found 51 percent or more at fault, recovery is barred entirely. For accidents before that date, a claimant could recover damages reduced by their percentage of fault even if that percentage exceeded 50 percent.
Preserving Evidence After a Truck Accident
Evidence in a defective parts case degrades quickly. The truck itself is the most important piece of evidence, and carriers frequently repair or scrap damaged vehicles within days of a crash. A spoliation letter sent to the carrier, the manufacturer, and any involved maintenance companies puts those parties on legal notice to preserve all physical evidence.
Commercial trucks manufactured after 2000 contain electronic control modules (ECMs) that record data similar to a black box in an aircraft. The ECM captures speed, braking patterns, engine RPM, and fault codes in the seconds before a collision. This data can show whether the brakes were applied, whether the system registered a malfunction, and how fast the truck was traveling at impact. Carriers are not required to preserve ECM data indefinitely, so obtaining it quickly is critical.
Maintenance records tell the history of the part that failed. Federal regulations require carriers to keep maintenance records for each vehicle for at least one year and records of inspections for at least 90 days. These records show when the part was installed, who installed it, where it was purchased, and whether prior inspections noted any issues. Driver logs and pre trip inspection reports provide additional detail about what the driver observed before the accident.
Caddo Parish courts in Shreveport's First Judicial District routinely handle commercial vehicle litigation. Filing a petition for injunctive relief to preserve evidence is a standard early step in these cases when there is reason to believe a party may destroy or alter physical evidence.
The Legal Process for Defective Parts Claims
A defective truck parts claim begins with an investigation to identify the failed component and the parties responsible for it. This typically requires retaining a mechanical engineer or accident reconstruction expert who can examine the vehicle, test the failed part, and render an opinion on whether the part was defective.
Louisiana requires that the claimant identify the specific defect under the LPLA framework. A general allegation that "something broke" is insufficient. The petition must state whether the claim is based on a construction defect, design defect, inadequate warning, or breach of express warranty. Each theory requires different proof, and the investigation determines which theory the evidence supports.
Discovery in these cases often involves obtaining manufacturing records from the part maker, including quality control data, testing protocols, and any prior complaints or recalls involving the same component. The National Highway Traffic Safety Administration (NHTSA) maintains a public database of recalls and technical service bulletins that can establish whether the manufacturer had prior knowledge of a defect.
These cases frequently involve substantial expert testimony. Metallurgists may analyze a fractured component. Engineers may test exemplar parts to demonstrate a design flaw. Economists may calculate the cost of an alternative design. Each expert opinion must satisfy Louisiana's standard for admissibility under Daubert v. Merrell Dow Pharmaceuticals, which requires that expert testimony be based on sufficient facts, reliable methodology, and proper application of that methodology to the case.
Settlement or trial typically follows the completion of discovery and expert reports. Because multiple defendants are often involved, each party's share of fault must be determined. The jury or judge allocates fault percentages among all parties, and each defendant pays only its proportionate share of the total damages awarded.