164. The following are major defects:
(1) no braking or an important reduction in the braking capacity on 20% or more of the wheels or combination of wheels for a road vehicle, by reason of the absence or inadequate operation of a component of the braking system;
(2) no braking on a wheel of the single active steering axle where the manufacturer equipped that axle with a braking system or where the road vehicle in question is a tractor truck manufactured after 7 May 1993;
(3) a crack that extends to the outer edge of the friction surface or on another part of a drum or disc;
(4) when the brakes are applied, a segment, bolt on rivet of the brake lining that touches the friction surface of the drum or disc;
(5) one of the components of the system that is insecurely mounted, missing, crimped, damaged, deteriorated or worn in a way that considerably reduces the good working order of the brakes; and
(6) 20% or more of the wheels or combination of wheels for a road vehicle are contaminated by oil or grease on the friction surface of a drum, disc or brake linings or are deeply rusted on both sides of the friction surface of a disc.