You installed fresh pads and rotors, and now the brakes make some noise. Is that normal? During the break-in (bedding) period, a little noise can be expected - but some sounds still point to a problem. Here is how to tell.
Why new brakes can be noisy at first
New pads and rotors have to mate their surfaces and lay down an even transfer layer of pad material - see brake pad transfer layer. Until that happens over the first few hundred miles, you may hear occasional light squeaks or a slight sheen of noise, especially when cold or damp. This usually fades as they seat.
The bed-in process
Properly bedding the brakes - a series of firm slowdowns - lays that transfer layer evenly and reduces early noise; see how to bed in brake pads and do brakes need breaking in. Skipping the bed-in is a common reason new brakes stay noisy or grabby.
Noise that is NOT normal
A constant loud squeal, grinding, or a rhythmic scrape is not break-in noise - it points to missing hardware, a stuck caliper, or contaminated pads; see why brakes squeak. Noise that gets worse rather than better over the first weeks needs inspection.
What to do
Bed the brakes in correctly, use fresh clips and lubricate the slides, and give quality pads a few hundred miles to settle. If real noise persists, recheck the install. Start with good pads and fresh hardware.