When to change brake pads: the clear signs of wear
In short
Brake pads should be replaced once the friction material has worn below roughly 3 mm, when the wear indicator starts squealing under light braking, or when the pad wear light appears on the dashboard. If you hear a harsh metal-on-metal grinding noise, the pad is completely gone and the car should not be driven until it is fixed.
The wear indicator squeal — your first warning
The most common sign is a sharp metallic squeal that appears under light braking and often disappears when you press the pedal hard. The noise comes from a small metal tab on the back of the pad, which starts touching the disc once the friction material has thinned out. It is a warning the manufacturer built in on purpose, not a fault, and it will not go away on its own. If you hear that squeal, the margin left is usually measured in a few hundred to a few thousand kilometres of normal driving — not months, and certainly not a whole season. On many modern cars the indicator is electrical rather than mechanical: a thin wire inside the pad is cut through by the disc and lights a warning on the dashboard directly, completely silently. Do not assume the pads are fine just because you cannot hear anything. Check visually as well, especially since many cars only carry sensors on one axle.
The minimum thickness rule: 3 mm of material
A direct measurement is still the most reliable criterion. A new pad typically carries between 10 and 12 mm of friction material, plus a steel backing plate of around 5-6 mm that does not wear. You measure the friction layer only, not the total thickness of the pad — this is where most first-time home checks go wrong. Workshop practice is to schedule replacement at roughly 3 mm remaining and never to go below 2 mm. Beneath that, the pad heats up far more quickly, stopping distances grow noticeably under repeated braking, and the rivet or backing plate risks touching the disc and destroying it. Some manufacturers publish their own, sometimes stricter, figures, so it is worth checking your handbook or calling us with the VIN if you want the exact value for your model. Measure at the thinnest point of the pad rather than in the middle: wear is almost always slightly tapered.
Pedal feel, fluid level and the dashboard light
As pads thin out, the caliper pistons extend further and the brake fluid in the reservoir drops gradually. A slow drop with no visible leak is usually the normal sign of pad wear rather than a fault. That is exactly why you should not keep topping the reservoir up: fill it to the brim and then fit new pads, and the fluid will overflow when the pistons are pushed back. A pedal that travels further than it used to, or feels soft and spongy, is a different matter entirely and is not explained by worn pads. That points to air in the system, degraded fluid or a leak, and in that situation the car should not be driven until it has been checked. A permanently lit red brake warning light deserves the same seriousness. The amber pad wear symbol is less dramatic, but it still calls for a booking rather than a delay.
Why front and rear pads wear differently
Under braking, the weight of the car shifts forward, so the front axle normally handles somewhere between 60 and 80% of the braking effort. The practical result is that front pads wear out two to three times faster than the rears, and on many cars you will fit two front sets for every rear set. That is not a problem — it is how the system is designed to work. What is not normal is uneven wear across the same axle, or even inside the same caliper. If the inner pad is much thinner than the outer one, the caliper slide pins are almost certainly seized or their boots are torn, and the caliper no longer floats freely. The same cause produces uneven disc wear, slightly higher fuel consumption and a car that pulls to one side under braking. Replacing the pads without cleaning and greasing the slides means the problem returns within a few thousand kilometres, with the money wasted.
What gets checked and replaced along with the pads
Pads are always replaced across the full axle, as a set of four, even if only one looks bad. A single new set on one side creates a braking imbalance between wheels, which is the opposite of what you want from a brake system. During fitting, the discs must be inspected, the caliper slides cleaned and greased with high-temperature grease, distorted anti-rattle springs and shims replaced, and new wear sensors fitted wherever the old ones were cut. Then comes bedding in. For the first 200-300 km, brake smoothly and avoid hard stops from high speed so the friction layer transfers evenly onto the disc. Skipping this step is one of the common reasons vibration appears shortly after a new set of pads. If you are not sure which set fits your car, the simplest route is to search the site by OEM code, or call us with the VIN and we will confirm it together.
Need the part we wrote about?
The catalogue carries the right products, priced in MDL with delivery across Moldova. If you are unsure about fitment, call us and we will check it against your VIN.
Frequently asked questions
How long can I drive once the pads start squealing?
Usually a few hundred to a few thousand kilometres of normal driving, though it depends on your braking style and route. Treat the squeal as an urgent workshop booking, not a flexible deadline.
Can I replace only the pads and keep the discs?
Yes, if the discs are above the minimum thickness stamped on them, with no pronounced lip, cracks or vibration. If the disc already has a clear edge lip, a new pad will not seat across its full face.
Do front and rear pads get replaced at the same time?
Not necessarily. Fronts usually wear two to three times faster, so it is normal to fit two front sets for one rear set. What matters is replacing each axle in full, never half of it.
Why is my brake fluid dropping with no leak?
Because the caliper pistons extend as the pads thin out and hold more fluid. That is normal, but if the level drops quickly, check the hoses and calipers for leaks immediately.