Why cars fail their MOT on brakes (and what it costs)

Brakes fail 6.10 percent of car MOTs and cause nearly 30 percent of dangerous defects. What fails, what it costs, and why it rarely stops a good salvage flip.

MOT DATA · 4 min read

Common and safety critical

Brakes fail 6.10 percent of car MOTs, and they are the second biggest source of dangerous defects after tyres, at 29.08 percent of dangerous items. So like tyres, they are common, safety critical, and mostly cheap to put right.

What fails

Worn pads and discs are the usual reason, along with binding or seized calipers, corroded brake pipes, low or contaminated fluid, and imbalance across an axle on the brake test. Corroded rear pipes are a common one on older cars that have spent winters on salted roads.

What it costs

Pads and discs for one axle are typically sixty to a hundred and fifty pounds in parts, more on bigger or performance cars. A caliper or a set of pipes adds to it, but brakes are generally a predictable, mid-cheap fix, and parts are widely available for common models, which keeps costs down.

The salvage angle

Brakes rarely stop a good flip, because the parts are cheap and plentiful and the work is straightforward. The thing to watch on a car that has stood after an accident is seized calipers and rusted discs from sitting, which is standing rather than damage. Budget a routine brake refresh on most salvage and let the Analyzer carry it as a standard line.