Hey there, i have a 98 4runner and am having an issue with the front brakes. They work fine most of the time, except if I hit a bump , not even a big one, or hit some gravel while braking. That is when they lock up, bad!!! The pedal drops to the floor, and the front brakes lock up completely until i come to a complete stop. I even had to remove the carpet square from my garage floor because sometimes when pulling into the garage my brakes would be fine until on the carpet, then they would completely lock up. As i said before the pedal completely drops to the floor and the front brakes lock up, only the front brakes the rears seem to be fine. Please help, as i just moved to a town where we get snow, and if it happens on gravel and small bumps, I would hate to see my wife drive my 4runner in the snow. hehehe.

 

Loose caliper? Stuck caliper? Bad ABS system problem.

 

Well the pedal going to the floor is usually an indication of a bad master cylinder. Not sure why bumps are causing the brakes to lock up though. Perhaps take it in (hopefully safely) for one of these "free" brake inspections at a shop?