Although there’s nothing fundamentally wrong with the ST220’s brakes, they’re probably the weakest point of the entire car. Ford made bold claims about the Mondeo’s stopping ability but they lacked feel even when new – possibly because the ST was saddled with the same 300mm vented front discs and 280mm solid rears as a base-model Mk3 – okay for a 113bhp diesel but somewhat lacking on a sports saloon with twice the power.
Fortunately, faults ( when they occur) are generally cheap and straightforward to fix. Most likely, you’ll experience seized rear brake calipers, notably on pre-2004 models. The handbrake mechanism is often to blame, although worn cables are common or the piston may also be sticking. Owners of early cars, in particular, become accustomed to renewing at least one rear caliper every year- or-so; fortunately, reconditioned replacements aren’t expensive.
ABS sensors also fail from time to time, making the warning light glow on the dashboard. Generally they’re easy to replace.
At the front, it’s advisable to swap the whole lot for Focus ST225 320mm discs, calipers and carriers, which are readily-available secondhand and bolt straight on. Every ST220 should have them!