2001 Corolla knocking sounds on braking

My Corolla recently started making a sporadic knocking sound when braking. It only seems to happen infrequently, but a couple of times I have noticed it happening when I go over a bump or crack in the road. Any clues as to what the issue might be?

Could be the wear sensors are starting to make contact. That would mean you are due for brake pads. Or something is binding in the brakes. There are slides that might need to be lubed. Probably time to ask a mechanic to pull the wheels and do a visual inspection.

Is it a single knock or clunk or multiple knocks that continue until you release the brake pedal?

Thanks @GeorgeSanJose‌. @Caddyman, its multiple knocks that keep on. The couple of times that I have noticed it now, it goes away when I release the pedal, but doesn’t come back when I re-apply the pedals.

I would have a competent brake mechanic take a look at your brakes and CV joints. Something is lose or broken or badly worn. Check your lug nuts… The knocking sound is a warning. Don’t ignore it…

There’s also the possibility that it could be caused by dry, worn ball joints; especially seeing as how you state this has happened while going over bumps or cracks in the roadway.

Ball joints can be lethal if one of them breaks so it would be a good idea to have that checked ASAP and avoid high speeds until that issue is clarified.