My 2010 corolla makes a knocking sound when I press a brake. Doesn‘t happen often, seems to only happen on wet/snowy road. Sounds like a metal bangs against metal in front of the car and my brake pedal starts to tremble. And the car does not slow down when it happens. What can it be? Any help much appreciated!
That's the ABS brakes working.
Sounds like your ABS (anti-brake skid) system is working. Check out your owners manual. It's sensing when one wheel skids it doesn't let the other brake grab, which would put you in a side slide or spin.
Perfectly normal and common when braking in slippery conditions. The anti-lock braking system (ABS) senses the wheels slipping, and will quickly pump the brakes. This will help keep your vehicle from sliding and help you maintain control when braking. When the ABS is active, you should not pump the brakes yourself, but keep the pressure applied steadily to your brake pedal. You will feel the brake pedal quickly pulse, and you'll also hear the ABS system in operation.
