{"nhtsa_id":51339,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1997-06-27","date":"1997-01-09","document_id":"106","mfr_campaign":null,"replaces":null,"component":"SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP","mfr_system":null,"summary":"NHTSA HAS MANDATED THROUGH FEDERAL REGULATION (49 CFR 571.121 \"AIR BRAKE SYSTEM\") THAT TRACTORS MANUFACTURED AFTER 3/1/97 PROVIDE CONSTANT POWER FOR TRAILER ABS. *JD","document":null,"url":"https://open.wenmarpro.com/bulletins/51339","components":[{"id":"brakes","name":"Brakes","parent":null},{"id":"abs","name":"Anti-lock brakes","parent":"brakes"}],"codes":[],"topics":[],"vehicles":[{"make":"HEIL","model":"HEIL","year_from":null,"year_to":null,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}