2024 Wabash National Van

The WABCO EBS Trailer Modulator (Part No. 4801070010), a 12-volt RSC valve installed on dry van trailers, intermittently retains residual pneumatic pressure in one delivery port without any active brake command. This causes a single wheel-end brake chamber to remain partially applied during highway operation, creating a sustained brake drag condition that is completely invisible to the driver — no warning lamps, no fault codes, no dash alerts, no detectable cab vibration or smell during early heat buildup. Over the course of normal highway operation, frictional heat accumulates at the affected wheel end beyond the thermal capacity of the drum and brake shoe assembly. The result is brake-shoe ignition and a trailer fire at highway speed, with no opportunity for the driver to detect or respond before flames are established. To date, 17 trailer fires have been reported as a result of this defect, resulting in loss of the trailer unit and sometimes full cargo. Approximately 1,200 trailers are believed to be equipped with this valve. All affected trailers have exhibited excessive brake wear consistent with chronic brake drag caused by the same pressure retention fault. Separate incidents have also resulted in severe wheel-end overheating, destroyed brake drums, seized components, and damage to axle hardware without progressing to a full fire. Third-party brake timing tests confirmed the anomalous pressure retention is isolated to the valve delivery port — not downstream brake hardware — and changes when electrical power is applied to the valve, implicating the internal solenoid or ECU mechanism. Independent inspections confirmed all other brake components were in proper condition, isolating the defect to this valve. The valve manufacturer has been contacted. No meaningful response has been received. The component is available for inspection upon request. Multiple fires are shown below, along with the valve.