Symptoms
- Squeal continues or started after new pads were installed
- May be worse when cold or on the first few stops
- No grinding, just noise
Likely causes
- CommonPads not yet broken inNew pads often need a proper break-in period (a series of moderate stops from speed) to bed in fully.
- CommonRotors not resurfaced or replaced along with new padsGlazed or worn rotors can cause new pads to squeal even though they're fine.
- PossibleAnti-squeal shims missing or not reinstalledThese thin metal/rubber shims dampen vibration between the pad and caliper piston.
- PossibleIncompatible or low-quality pad compoundSome cheaper pads are simply noisier by design.
- Less commonCaliper hardware not lubricated during installationDry slide pins can cause uneven pad contact and noise.
What to do
- Perform a proper brake break-in if it hasn't been done: several moderate stops from around 35–40 mph without coming to a complete stop, allowing brakes to cool between each.
- Check whether the rotors were resurfaced or replaced at the same time as the pads.
- Ask the shop (or check yourself if you did the work) whether anti-squeal shims were installed.
- Check if caliper slide pins were greased during the installation.
- If squeal continues after proper break-in, have the shop inspect the installation and consider a different pad compound.
- Have rotors resurfaced or replaced if they weren't addressed during the original pad job.
Tools and parts
Brake pad hardware kit (shims, clips)Search: “brake hardware kit for your car make and model”
When to call a pro
Go back to the shop that installed the pads if squeal continues after a proper break-in, since it may point to an installation issue covered under their service.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.