If judder or vibration happens in the very early life of the vehicle it should be taken back to the installing mechanic to check for brake disc (rotor) run out.

If rotor run out problems are not eliminated at the early onset of vibration or judder, they will become more permanent and worse and will eventually damage the rotor causing its replacement to be necessary to resolve the problem.

Judders and vibrations can also be caused by imbalance of the tyres, a seized brake calliper, or a poor surface condition on the brake disc (should be turned or replace on pad installation in all cases).

The ways to eliminate judder are as follows. First of all check that the disc was installed and was running true with a dial gauge, which should be done by your local mechanic.

Vibration or judders at low speeds are always associated with rotor run out. Vibrations or judder at high speeds (70 - 100 mph) are what we call hot judder and are normally associated with over heating of the brake disc.

This is usually because of a low quality brake rotor casting (in which case the customer needs to be asked who’s rotor he was using). This is only remedied by replacement of the rotor.

The other cause of vibration is known as “disc thickness variation” which is a condition generated when the rotor wears thick and thin due to incorrect installation of the rotor by the installing mechanic (in other words not running true from first installation).

Information from 'EBC Brakes Direct'