New Vehicle. The lift axle installed on a vehicle shall have a manufacturer's, second-stage manufacturer's, or authorized dealer's certification to carry a minimum axle load of 13,500 pounds, with a maximum tolerance of minus 1,500 pounds, or higher if the load imposed by design is greater. The lift axle shall be designed to ensure sufficient air pressure which will maintain a minimum axle load capacity of 13,500 pounds, with a maximum tolerance of minus 1,500 pounds, when fully engaged on an evenly loaded vehicle with a GVW of 70,000 pounds. All components on the vehicle shall be certified by the manufacturer, second-stage manufacturer, or authorized dealer that they are of a design and type capable of safely carrying the load induced by a four or more axle vehicle with a minimum load capacity of 13,500 pounds, with a maximum tolerance of minus 1,500, pounds on the lift axle when fully engaged at 70,000 pounds. The lift axle shall be designed so that when in the down position the axle can only be fully engaged. Switches and Controls. A switch capable of only fully engaging or disengaging the lift axle may be located in the cab of the vehicle. An air pressure adjustment control may not be located in the cab of the vehicle. A standard automotive air pressure valve for the lift axle shall: Be supplied on each vehicle that uses a lift axle; Have an external valve stem; Be located on the outside of the passenger side of the vehicle towards the rear of the cab; and Be readily accessible and visible for examination. A vehicle shall be certified by a manufacturer, second-stage manufacturer, or authorized dealer to be in compliance with the provisions of this section. Existing Vehicles. All components including a lift axle added on a retrofitted vehicle shall meet the design requirements specified in §A of this regulation. The owner of a retrofitted vehicle shall comply with the provisions of COMAR 11.15.20.05.