Centre for Road Safety

Brake Modifications - Overview

[Cover of the Brake assessment manual. Reads: Brake assessment manual, October 2103, NSW Government, Transport for NSW.]

Narrator: This video supports the key steps of each assessment method in the Brake Assessment  Manual.

[We see the view of the front left wheel of a white commodore as it travels on a test track on a sunny day.]

Narrator: Downloadable at roadsafety.transport.nsw.gov.au

Graphic: For more information visit roadsafety.transport.nsw.gov.au

[The left front wheel of the car is shown again, then a shot of the station wagon on the track.]

Narrator: A vehicle’s brakes are its single most important crash avoidance system.

[The station wagon suddenly brake and come to a stop. A close-up of a mechanic’s hands show him using a spanner to adjust the braking system in the engine bay of a vehicle.]

Narrator: Modifying your vehicle could affect its braking system.

[The mechanic uses pliers to work on the braking system.]

Narrator: When a vehicle is modified in a way that could affect its safety, it must be assessed by a certifier.

[The mechanic is shown putting the lid on the brake fluid reservoir.]

Narrator: There are two parts to the assessment.

[A certifier inspects the braking system of the car. He uses a spanner to adjust the system, then closes the bonnet of the car.]

Narrator: The certifier first gives the modified vehicle a thorough inspection. When they are satisfied that the modification has been done properly, and the vehicle is safe, they will give you a compliance certificate.

Narrator; Table one in the manual gives a list of modifications that affect your vehicle’s brakes that need to be assessed before registration.

Graphic: Modifications that require brake system assessment. Some examples of modifications are:

  • Fitting disk brakes to the front of a vehicle with brake calliper adapting brackets
  • Fitting replacement front suspension and brakes from a different make and model
  • Replacing the entire braking system with a combination of components either from a production vehicle or an after-market brake component manufacturer
  • Modification of alteration to electro-hydraulic full power braking system
  • Wheels and tyres in excess of plus or minus 7 percent and which have not been previously tested
  • Change in the mass on the axles by 10 percent or more and brakes unchanged from those fitted and tested prior to the mass change

[The car is shown entering a test garage, with the wheels aligned on metal testing plates.]

Narrator: The range of tests needed depends on the type of modifications to your vehicle.

[Two men are shown in the car as it is driven on the test track. beside the driver, a certifier sits in the passenger seat with a computer on his lap. A measuring instrument on the dashboard is connected to the laptop.]

Narrator: The manual will guide you on the different methods for assessing your modified vehicle.

[The car approaches from the distance on the test track.]

Narrator: Replacing parts and components with equivalent parts and components, or using optional parts and components approved by the vehicle manufacturer, are not considered to be a modification and don’t need assessing.

Graphic: If you are simply replacing the components or using approved vehicle manufacturer’s parts, no assessment is required.

Narrator: If you intend to modify your vehicle, there are four methods available for having your vehicle assessed.

  1. Using approved after-market components.
  2. Using components previously tested on a similar vehicle.
  3. Completing the installation checklist and obtaining data from a static brake test machine.
  4. Dynamic road tests.

Graphic: For all other modifications there are four methods available for having your vehicle assessed:

  • Method 1, Approved aftermarket components
  • Method 2, Tests to similar vehicles
  • Method 3, Static brake test
  • Method 4, Dynamic road tests

Narrator: You should decide which method you want to use before you modify your vehicle. Method 1 doesn’t require any tests. For method 2, providing there are already tests done to a similar vehicle, no further tests are required.

Graphic: Method 1 Approved aftermarket components.

[Four photos displayed on the screen show a brake caliper, a brake hose fitting, a container of brake fluid and a set of ceramic brake pads.]

Narrator and graphic: If you modify your vehicle using approved after-market components, it will not require any testing. If you intend to use this option, you must make sure the components are compatible to your vehicle and they are installed according to the component manufacturer’s instructions. Once the modification is completed, you must arrange to have the modified vehicle assessed by a certifier.

Narrator and graphic: The certifier will simply confirm:

  • The compatibility of the components
  • That they have been properly installed, and
  • Where the components are fitted in the vehicle, the vehicle is in good condition and free from rust and other defects.

Graphic: The four methods: Method 1, Approved aftermarket components; Method 2, Tests to similar vehicles; Method 3, Static brake test; Method 4, Dynamic road tests

Graphic: Method 2, Tests to similar vehicles

Narrator: You can use method 2 when a modification uses the identical braking system or components to those that have been used in a similar vehicle that has been previously tested.

Graphic: Acceptable tolerances between similar vehicles.

Graphic shows outline diagrams of similar sized vehicles, indicating Power: plus 20 per cent, Centre of gravity: plus or minus 50mm, wheel base: plus or minus 20 per cent, tyre size: plus or minus 7 per cent, individual unladen axle mass: plus or minus 10 per cent.

Narrator: For example, when common modifications are done to a group of similar vehicles, such as vehicles in a motoring enthusiasts club. This method can be used on individual vehicles, or when identical components are used in assembling a number of cars from the same kit.

Narrator: Put simply, this method recognises that the test results for a modified vehicle may be applied to another vehicle. In all cases, the certifier must have the results of the test done on the original vehicle. As a part of the assessment, the certifier must ensure the vehicle is similar enough to the tested vehicle, and the components are the same.

Graphic: The four methods

Graphic: Method 3, Static brake test

[The car is driven into a test garage, with the wheels aligned to drive on top of the metal test plates.]

Graphic and narrator: If you choose Method 3, you’ll  need to:

  • Make sure the components are properly installed – use the checklist in the manual to guide you
  • Take the vehicle to an approved facility for a series of static brake tests
  • Take the vehicle, the completed installation checklist and the above test results to the certifier for assessment.

Narrator: The certifier will either give you a compliance certificate or request more testing.

Graphic: Method 3, using a plate-type test machine

Graphic: Basic performance test

[The car is driven on to the metal test plates and stopped to test the front brakes.]

Narrator: The basic performance test is completed for all modified vehicles and assesses brake performance.

[The car moves forward then stops to test the rear brakes.]

Narrator: The same procedures are then used for all of the tests. Examples of other static brake tests include:

Graphic: Method 3, Test D, part 1 – Front brakes disconnected

[A close-up of a mechanic’s hands show him disconnecting the front brakes on a vehicle’s braking system.]

Narrator: The front brakes are disconnected and the vehicle is tested on the static brake test machine, and checks that the rear brakes can bring the vehicle to a stop with the front brakes disconnected.

[The car is driven into the test garage, where it stops on the metal testing plates.]

Narrator: The results show the front brakes did not operate during the test and all the braking force was applied by the back brakes.

Graphic: Test D – Example of data from a test with front brakes disconnected, plus graphs showing the force of the rear brakes

[Close-up shows the mechanic reconnecting the front brakes.]

Narrator: Remember to reconnect the front brakes at the end of the test.

Graphic: Method 3, Test D, part 2 – Rear brakes disconnected

[A mechanic under the car disconnects the rear brakes.]

Narrator: The rear brakes are disconnected and checks that the front brakes can bring the vehicle to a stop with the rear brakes are disconnected.

[Close-up of the rear wheel of the car stopping on the metal test plate.]

Narrator: Remember to reconnect the rear brakes at the end of the test.

[The mechanic reconnects the rear brakes.]

Graphic: Method 3, Test E – Booster disconnected

[The car is driven into the test garage, where it stops on the metal testing plates.]

Narrator: The vehicle is tested to ensure the brakes can bring the vehicle to a stop with the booster disconnected.

Graphic: Close-up shows the mechanic reconnecting the booster.

Narrator: Remember to reconnect the booster at the end of the test.

Graphic: The 4 methods

Graphic: Method 4, Dynamic road tests

Narrator: Dynamic tests are conducted on a road or a test facility.

[The car travels on a straight stretch of road at a test facility.]

Narrator: If you do dynamic tests on the modified vehicle, you should use a licensed and competent driver.

[Interior shot of the car shows a driver with licensed certifiers in the passenger and rear seat positions.]

Narrator: You should also engage a certifier to conduct or supervise the tests.

[A certifier closes the bonnet of the car after an inspection. Close-ups show the braking system in the engine bay of the vehicle, a mechanic with a pair of pliers checking the braking system and topping up the brake fluid reservoir. The certifier bends over under the bonnet of the vehicle to adjust the braking system.]

Narrator: Before any dynamic tests are done, the vehicle must be checked to make sure it is roadworthy and can safely do the tests.

[The car is shown in the distance travelling on the test road. Interior shot of the car shows the driver at the wheel and the certifier in the passenger seat.]

Narrator: If the tests are to be done on a public road, approval is required from the local council, and Roads and Maritime Services, who may impose conditions on the tests, which must be obeyed.

[The car is shown in the distance travelling on the test road. A wide shot shows the empty, straight stretch of test road.]

Narrator: The stretch of road that you use must meet the test conditions described in the manual.

[A view from the passenger seat of the moving vehicle shows the straight, flat section of test road. There are no other cars on the test road. A shot out the side window shows a rural view with hills in the distance.]

Narrator: If you aren’t able to use a public road for a test, a suitable venue must be used.

[Shots show the certifier installing computerised test devices in the front and rear seats of the vehicle. He also attaches a device to the brake pedal of the car. A close-up shows specialised recording devices on the road beside the car.]

Narrator: Appropriate equipment must be used to measure and record the test data. The following types of equipment must be used as a minimum.

Graphic and narrator: An inertial type direct reading deceleration meter that is capable of reading the average fully developed deceleration.

[Close-up shows the deceleration meter and recording device in the back seat of the car.]

Graphic and narrator: A pedal force gauge.

[Close-up shows a pedal force gauge being taped to the brake pedal.]

Graphic and narrator: A device such as a fifth wheel or GPS for measuring speed.

[Close-up shows a device being fitted to the dashboard of the car.]

Narrator: For more information, including a demonstration of the dynamic tests, visit roadsafety.transport.nsw.gov.au

[The car travels on the test track and comes to a stop.]

Graphic: For more information visit roadsafety.transport.nsw.gov.au

Narrator: Transport for NSW acknowledges the following organisations for their assistance in producing this video.

Graphic: Acknowledgements. Syriops for the use of a modified vehicle, Workshop Solutions for the use of the static brake test and its facilities, V-Sport for the use of brake components.

Graphic: NSW Government, Transport for NSW. The tests were done on a closed test facility at Goulburn Airport

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Dynamic Road Tests

[Different shots show a test track and measuring devices being taped to the brake pedal of a car, fitted to the dashboard and installed in the rear seat area.]

Narrator: This video provides a practical demonstration of the dynamic road tests specified in the Brake assessment manual under Option 4, for assessing a modified vehicle or an individually constructed vehicle.

[A white station wagon is shown driving though a puddle of water as it enters a test track area. It is a fine day and there are rural views in the distance around the track.]

Narrator: The tests may also be required, based on the certifier’s assessment of the data provided under Option 3.

[The car comes to a stop on the track. An interior shot of the car shows a driver at the wheel and a certifier in the passenger seat using electronic measuring devices.]

Narrator: The tests should be viewed in conjunction with the Brake assessment manual, which provides details of how to do the tests and how to use the results of the tests.

[Multiple shots show the car from different angles on the test track, before it comes to a stop.]

Graphic: Method 4. Test D, F & G: Partial failure test front and rear; proportional valve failure; ABS failure

[Different shots show a mechanic’s hands as he removes a hose from the braking system of the car, the mechanic closing the bonnet of the car,and  the view out the front window of the car as it travels on the large test track.]

Narrator: Test D checks that the master cylinder in a split-service braking system has enough displacement to operate at individual circuit, in the event of one of the circuits failing. Do not simply clamp off the brake hose, as this does not simulate a failure in a circuit.

Graphic: Test conducted on a closed track

[The car slowly comes to a stop on the track.]

Narrator: Tests F and G are required to ensure that the vehicle can be safely brought to a stop if either the front or rear brakes fail. These tests also verify if the vehicle’s ABS is working properly.

[The car travels along the test track.]

Narrator: The front and rear brakes are tested separately.

[The car slowly comes to a stop.]

Both tests are done with the vehicle lightly and heavily loaded, travelling at 55 kilometres per hour.

Graphic: Method 4. Test E: Booster failure

[Close up shows a mechanic removing the booster hose from the car’s braking system.]

Narrator: The booster failure test checks that the vehicle can stop if the booster fails. To do the test, the booster is disconnected.

[The car travels along the test track.]

Graphic: Test conducted on a closed test track

Narrator: The vehicle should be tested with the maximum loaded test mass and the vehicle in gear.

[A shot of the front left wheel of the car shows it coming to a stop.]

Narrator: To pass this test, the modified vehicle needs to meet one of four conditions in Table D of the manual.

[The car travels on the track and comes to a stop.]

Graphic: Method 4. Test H: Spike stops

[The car travels on the test track.]

Narrator: The spike stop test applies sudden and instantaneous load to the vehicle to test the function of the brake components under duress. The test is performed at 55 kilometres per hour in neutral.

Graphic: Test conducted on a closed track

[The car comes to a stop.]

Narrator: Ten stops are required if the vehicle is lightly loaded, or five stops if the maximum loaded test mass is used.

[We see the view through the windscreen as the car travels on the track.]

Narrator: Care should be taken not to lock the wheels during this test, as that can damage the tyres. The tests should be repeated if the wheels lock during testing.

[The car is shown on the track and comes to a stop. The wheels do not lock.]

Graphic: method 4. Test I, Wheel lock

Narrator: This test is used to check the front wheels lock before the rear wheels.

[The car travels in the distance on the test track.]

Graphic: Test conducted on a closed track

[A shot shows the front left wheel of the car as it travels on the track. We then see the car travel into the grass area beside the track.]

Narrator: This test should be performed with the tyres between 65 and 100 degrees, and should be performed on a surface with a low coefficient of friction, like grass, or a wet surface.

[The front wheels of the car lock up as the vehicle comes to a stop on the grass.]

Narrator: The front wheels should lock up before the rear wheels, and this should be obvious to the naked eye.

Graphic: Method 4. Test J: Type-0 engine disconnected

Narrator: Test J records how the vehicles brakes perform when they are cold and the vehicle is coasting.

[A certifier measures the temperature of the car’s brakes with a device that records 82.3 degrees on its screen.]

Narrator: The temperature of the brakes must be between 65 and 100 degrees at the beginning of the test.

[A shot of the left front wheel of the car shows it set off for another test on the track.]

Narrator: The test is done to see how the brakes perform within the temperature range generated during normal and extreme driving conditions.

Graphic: Test conducted on a closed track

[The car approaches from the distance on the track and slowly comes to a stop.]

Narrator: The test is performed with the vehicle heavily and lightly loaded. The test speed depends on the modification.

Graphic: method 4. Test K: Type I heating procedure

[Different shots show the car travelling and braking on the test track.]

Graphic: Test conducted on a closed track

Narrator: This tests the brakes functionality when they are being heated beyond their normal operating temperatures. This test is performed by applying and releasing the brakes 15 times in total to the vehicle travelling 80 kilometres per hour, which should reduce to 40 kilometres per hour under braking.

Graphic: Method 4. Test L: Type I hot procedure

[The car makes a turn on the test track and travels into the distance.]

Graphic: Test conducted on a closed track

Narrator: This test checks brake performance when they are hot. The test is performed with the vehicle heavily and lightly loaded.

[The car approaches and comes to a stop.]

Narrator: The test speed depends on the modification. The test is performed immediately after Test K and is performed under the same conditions as Test J, although the brakes’ temperature can be different.

Graphic: method 4. Test M: Type I recovery procedure

[Different shots show the car travelling on the test track.]

Graphic: Test conducted on a closed track

Narrator: This test checks brake performance when they are hot and have been brought back to a normal temperature range, as is done immediately after Test L.

[The car comes to a stop.]

Narrator: The vehicle is stopped four times from 50 kilometres per hour, to a complete stop, with the engine connected.

[The car turns and accelerates back down the test track.]

Narrator: Immediately after each stop, the car should be accelerated at its maximum rate up to a speed of 50 kilometres per hour, and that speed should be maintained for at least 1.5 kilometres until making the next stop.

[The car stops, then turns and heads back down the test track.]

Narrator: If the test facility is not long enough to allow the vehicle to travel for 1.5 kilometres, a shorter distance can be used.

[The car approaches and comes to a stop.]

Narrator: Care is required if the distance used is too short, the brakes don’t get enough time to cool down between test runs, and they could overheat.

[Different shots show the car turn, head back down the test track, then approach and stop.]

Graphic: Method 4. Test N: Type I recovery performance

[Different shots show the car travelling on the test track, before it comes to a stop.]

Graphic: Test conducted on a closed track

Narrator: This test checks the brakes recovery when they have been brought back to their normal operating temperature range, and is done immediately following Test M. The test is conducted at varying speeds, depending on the modification. The braking system is measured in the same conditions as for Test J, although the brakes’ temperature conditions can be different.

Graphic: The tests were done on a closed test facility at Goulburn Airport.

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