The effects of torque on the proper maintenance and function of a vehicle are difficult to overstate. From the basic functioning of a steering wheel to the intricate details of the engine, angular momentum plays a role in virtually every mechanism that makes it possible for a car to function — including the brakes.
If brakes are not subject to a thorough torque fatigue test before sale, the results could be dire. A car with poorly-working brakes is a danger not only to its driver, but also to the drivers of every other vehicle on the road with it. Considering the complexity of these devices, and the number of fasteners required for their proper function, such testing should be thorough and performed by a trusted organization.
A full torque test has two components: in-line and reaction, both of which are critical to ensuring the brake is working correctly. The former measures how much angular force is required to turn a particular part. The latter measures how much force is needed to keep it from rotating. For a fastener to work properly, it must be readily movable when it should be in motion, but completely immobile otherwise.
While the conventional approach is to simply turn until a defined torque value is reached, that methodology is susceptible to oversight, such as a faulty installation. For example, if a fastener was incorrectly threaded, it could reach maximum torque value earlier than anticipated, which would not show up in a less-than-thorough test. Instead, a more comprehensive test is required.
The worst time to find out that a set of brakes has been inadequately examined is once on the road. Torque testing is a key component to ensuring this does not happen.