(NCT) Manual 2010 - Road Safety Authority

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NATIONAL CAR TEST (NCT) MANUAL 2010
PARKING BRAKE PERFORMANCE
Method of Testing
Roller Brake Test
1. Normally this test will follow the service brake test and the same general precautions apply (see ‘Method of Testing’ and
‘Notes’ for Service Brake Performance).
2. With the roller brake test machine driving each road-wheel, apply the parking brake slowly until each road-wheel is just at
the point of slip relative to the rollers, or until sufficient braking is achieved – whichever occurs first. Note the braking effort
indicated from the brake of each road-wheel, and calculate the total braking available. Calculate the braking efficiency as a
percentage of the vehicle test weight.
3. If the parking brake is a transmission brake, all wheels on the axle that are braked by the transmission brake must be driven by
the roller brake test machine at the same time.
Decelerometer Test
If the vehicle is of a type which cannot be tested on the roller brake test machine, it should be subject to a decelerometer
test as follows:
• With the vehicle on a reasonably level road, place the decelerometer on the floor of the vehicle. Follow the manufacturer’s
instructions and set it in the zero position.
• Drive the vehicle at a speed of approximately 32km/h (20mph). Apply the parking brake and note the reading
on the decelerometer.
ITEM
Vehicles registered before the 1st July
1964 with a single line brake system
Vehicles registered on or after 1st July
1964 with a single line braking system
Vehicles with a dual line
braking system
REASONS FOR FAILURE
1 Braking effort less than 20% of the test weight of the vehicle.
2 Braking effort less than 27.5% of the test weight of the vehicle.
3 Braking effort less than 16% of the test weight of the vehicle.
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