49 C.F.R. § 393.49 Single valve to operate all brakes.
Title 49 - Transportation
Every motor vehicle, the date of manufacture of which is subsequent to June 30, 1953, which is equipped with power brakes, shall have the braking system so arranged that one application valve shall when applied operate all the service brakes on the motor vehicle or combination of motor vehicles. This requirement shall not be construed to prohibit motor vehicles from being equipped with an additional valve to be used to operate the brakes on a trailer or trailers or as provided in §393.44. This section shall not be applicable to driveaway-towaway operations unless the brakes on such operations are designed to be operated by a single valve.
Title 49: Transportation
PART 393—PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION
Subpart C—Brakes
§ 393.49 Single valve to operate all brakes.
