How do brake testers work?
It consists of an automated weighing system that accurately calculates the braking efficiency of the vehicle. The brake tester consists of weighing cells on each side of the unit with a safety roller that detects whether a vehicle is present in the tester – this will also monitor any tyre slippage.
How do you perform a brake performance tester?
Service brake test
- Position the wheels on the brake tester and ensure they are located reasonably centrally in the rollers.
- Leave the rollers running and note whether a significant brake effort is recorded from either wheel, indicating that a brake is binding.
At what speed is the brake test carried out?

the test must be carried out at the speeds prescribed for each type of test; if the maximum design speed of a vehicle is lower than the speed prescribed for a test, the test shall be performed at a speed that is set at a multiple of 5 km/h that is 4 to 8 km/h less the vehicle’s maximum speed.
What is brake performance tester?
A performance-based brake tester (PBBT) is a machine that assesses the braking performance of a vehicle. This is done through direct measurements of the brake forces at each wheel end, axle or for the entire vehicle.
How do you measure brake force?
It can be calculated by multiplying the “coefficient of road adhesion” to the weight of the vehicle. The coefficient of road adhesion is the maximum value of friction present on that road.
How do you calculate automatic brake imbalance?

Divide the vehicle’s weight by the total brake effort, and then multiply the number by 100 to get the brake efficiency percentage. Weigh everything inside your car as well, because that will affect the brakes.
How do garages test brakes?
A decelerometer is a hand held device for measuring dynamic braking forces during a vehicle road test. A vehicle decelerometer operates as if it were, and it could also be known as, an accelerometer as it calculates braking efficiency by using those forces captured during a vehicle’s deceleration.
How should a road brake test be carried out?
Best practice is to test the vehicle/trailer in a laden condition. The guide strongly advises that brake testing is done using a calibrated roller brake tester to measure the brake performance at each individual wheel as well as the overall efficiency on every safety inspection.
How many clicks should handbrake have?
A normal handbrake should take between 5 and 8 clicks – more than this and it could be too tight, causing damage to the rear brakes and less than 5 means it’s likely to be dragging and could fail completely.