if it's a single abrupt change and it's always in the same direction then it's a caliper problem... no matter how stiff your FCAB's are if you have a caliper in the front which isn't working properly the car will pull hard to the side of caliper which is working. The 'tell tale' sign that the FCABs are going bad is twitching when hitting bumps and it twitches back and forth not just in one direction.
If the car is making a sudden pull or twitch to one direction when hitting the brakes and that direction is the same every time than you have a caliper problem.
Lesson #1 is diagnosis... if the problem shows itself when performing a specific task (in this case braking) than the problem is most likely within the system involved in performing that task (in this case brakes)
Last edited by WFRFitness; 10-15-2010 at 12:52 PM.