I have noticed a strange knocking sound when I press the brake pedal all at once that is felt at my foot.However , when I press the pedal gradually nothing is heard or felt. I have the brake examined visually by a mechanic , everything seem normal. Any suggestion is appreciated.
The noise is probably the ABS kicking in…A pulsating pedal is normal when the brakes are applied hard with abs brakes.
Yes, that is a possibility, especially if the OP’s tires have poor traction as a result of treadwear or age. None of us know the age or condition of the tires, but the OP might want to consider that his tires could be the reason for ABS activating whenever he brakes hard.
Another possibility is a warped brake rotor.
You are right. My tires are more than 3 years old and their tread depth is about 2 mm. So I guess they need to be replaced soom.Thank you.
Just keep in mind that 2 mm of tread depth can be deadly when driving in the rain, so I hope that you replace them really soon. If the ABS was kicking-in on dry roads, just imagine how little traction you will have on a wet road. (Hint… none)