System: fuel; liquid petroleum gas (lpg).vehicle description: travel trailers equipped with a two-stage automatic change-over lpg regulator manufactured by marshall gas controls. Note: if the regulator IS not replaced with a reasonable time free of charge, please contact fleetwood at 1-800-854-4755 or marshal gas controls at 1-800-396-1322.also contact the national highway traffic safety administration's auto safety hotline at 1-800-424-9393.