38. Where a vehicle is equipped with full pneumatic service brakes, the brake system shall comply with the following standards:
(1) the compressor shall be capable of raising the air pressure in he system from 350 to 620 kPa in less than 3 minutes where the engine runs at no more than 1,200 revolutions per minute;
(2) the pressure regulator shall start the compressor before the air pressure in the system reaches 550 kPa and shall stop it where the air pressure is between 805 and 945 kPa.
(3) the low pressure warning light or buzzer shall activate where the air pressure in the system is less than 380 kPa;
(4) the compressed air reserve shall be sufficient to permit one full service brake application without lowering the reservoir pressure by more than 130 kPa where the air system is fully charged and the motor has just been stopped; however, where the test is performed on a combination of road vehicles, the pressure may not be lowered by more than 20%;
(5) the drain tap and the non-return valve of each air reservoir shall be present and adequate;
(6) the fast exhaust valves and the relay valves shall be securely fixed and let the air out quickly through the holes provided by the manufacturer;
(7) for a tractor truck, the protection valve of the tractor truck and the air supply valve of the semi-trailer shall operate so as to avoid a complete air loss in the system of the tractor truck should the air hoses between the tractor truck and the trailer or semi-trailer break or disconnect; in such a case, the valves shall preserve a minimum air pressure of 420 kPa in the system of the tractor truck;
(8) the brake cylinders, the brake chambers or the slack adjusters installed on a single axle shall be of the same type and size, be securely fixed and none of their components or related parts shall be so corroded that their resistance is reduced, or so worn that the good working order is affected, nor shall they be missing, damaged, cracked, broken or of a capacity or quality below that prescribed by the manufacturer;
(9) the stroke of the actuating rod of the brake chamber shall not exceed the maximum adjustment specified by the manufacturer where the air pressure in the chamber is kept at about 620 kPa and the variation in the travel of the actuating rods on a single axle shall not exceed 6.4 mm;
(10) for a single-unit vehicle, the air pressure shall not lower by more than 20 kPa within one minute where the service brake is fully applied while the air pressure is at the maximum, the engine is off and the parking brake is released;
(11) for a combination of road vehicles, when the air pressure is at the maximum, the engine is off and the parking brake is released, the air pressure shall not decrease by more than 28 kPa within one minute for a tractor truck coupled to a trailer or semi-trailer and more than 35 kPa for a tractor truck coupled to 2 semi-trailers or to one semi-trailer and a trailer with the service brake fully applied;
(12) the radial stroke between the camshaft and its pads shall not exceed 2.1 mm, the position of the roll centre on the cam shall not be more than 120 degrees from the lowest part of the cam where the brake linings touch the drum.