(1) If a B-double or road train is fitted with brakes that operate using compressed air, the braking system of the motor vehicle must comply with subrules (2) and (3) when:
(a) the pressure is measured in an 800 millilitre vessel connected by a 2 metre pipe with a bore of approximately 13 millimetres to the coupling head of the braking system; and
(b) the air pressure before the brakes are applied is not under:
(i) the average of the maximum and minimum pressures in the operating pressure range specified by the vehicle's manufacturer; or
(ii) if there is no manufacturer's specification – 650 kilopascals.
(2) The pressure must reach at least 420 kilopascals within 400 milliseconds after the rapid and complete application of the foot-operated brake control.
(3) After the brakes have been fully applied, the pressure must fall, within half a second after the release of the foot-operated brake control, to 35 kilopascals.