A warning light is the last signal a brake system sends, not the first. Long before it comes on, most drivers notice something small: the pedal sits a bit lower, takes longer to bite, or pulses under the foot. Those changes are easy to rationalize, which is exactly why they go unreported until a repair becomes urgent.
The signs worth noticing
Pay attention to a pedal that feels softer or sinks further than it used to, a car that pulls toward one side when you brake, a grinding or squealing noise that appears when you stop, a pulsing sensation through the pedal or steering wheel, or stopping distances that feel longer than they did. Any of these deserves a closer look, and more than one at a time deserves a prompt visit to a shop.
Write down what you noticed
Keep a short note on your phone or in the glovebox. Record what you felt or heard, when it happened, and the conditions: cold morning, wet road, hard stop, long downhill. A note like this helps a technician find the problem faster, and it gives you a clear record if a question ever comes up about when the symptom started.
When to stop driving
If the pedal sinks close to the floor, the car pulls hard to one side while braking, or the brakes fail to slow the car normally, do not keep driving it to see what happens. Arrange a tow or a ride instead. This is basic vehicle safety, not a judgment about any contract, and it applies whether or not you have any kind of protection on the car.
Why this matters for a service contract
Many service contracts, and many warranties, treat a problem that was already developing before the paperwork was signed differently from one that began afterward. Knowing the signs yourself makes it easier to answer honest questions about the car's condition. Read the contract's wording on known conditions before you buy, and use the published tables on this site to see what each company says it does with them.