GENERAL MOTORS issued a recall on the W3500W4500, and W5500 models

On certain vehicles, the bolt that connects the engine lubrication oil pipe to the vacuum pump may not have been tightened properly during vehicle assembly. If not adequately tightened the bolt may loosen after prolonged vehicle operation, which can result in oil seepage or leakage from the packing seals. Normally, as oil is lost, the oil warning lamp will illuminate and there may be abnormal engine noise. However, if the problem is not addressed, the loss of oil can cause engine seizure. If the engine seizes while the vehicle is being driven, the vehicle may experience sudden deceleration, which could result in a crash causing property damage and/or personal injury. Correction: Dealers will replace the packing seals and tighten the bolt to specified torque.