The most likely cause is that your front rotors have a runout or thickness variation problem. Or in more common terms...the rotors are warped. Even a rotor that is off by a few thousandths of an inch can cause brake pedal pulsation or a vibration in the steering wheel when the brakes are applied. Yes...even at 30,000 kms...especially if you are doing a lot a braking in city driving.
Originally Posted by kulot
The repair in this case would be to re-surface or replace the rotors. My personal preference is to just replace them. In my experience, resurfacing rotors tends to fix the issue temporarily. The pulsation/vibration usually returns.
View my fuel log 2015 Mirage ES 1.2 manual: 51.3 mpg (US) ... 21.8 km/L ... 4.6 L/100 km ... 61.7 mpg (Imp)