I have quite a bad vibration through the steering wheel when braking at high speeds, 120kph plus, especially when braking hard. I can't feel it through the brake pedal and the steering doesn't shake when driving so i don't think wheel balancing is the issue. Discs and pads were changed recently and have only done abut 10k, however i am having to top the air in two tires once a week or so. Could the imbalance of air cause this problem, or could it be a suspension issue?
Cheers.