knock noise when braking

[CBP_knight21]

Hello everyone!

I have an issue with what I think are the front brakes. When coming to a stop at very low speeds (like <5mph) I hear a "knock" noise while very lightly pressing the brake pedal. It does it in reverse as well. After I have been driving for a while it does not do it. I assume its because the car is hot. It only knocks once and its only either going forward or reverse. I did some googling and found some people said brake pad play but I dont understand why it would just start to do it after driving the car with the same HONDA oem pads for 8 months. I do have EBC slotted rotors front and rear but I put them on at least 3 months ago. Front pads are oem Honda pads and rear are Akibono which have been on the car as long as the rotors. I know I cant be the only one with this problem. Any help would be greatly appreciated!

 

[webby]

another member had their pads not seated properly that had issues on the oem rotors. Could the pad edge be catching a slotted grove on yours? Maybe take a wheel off and see what the wear on the pad surface looks like

 

[Darkout]

This sounds exactly like brake pad shift and really isn't an issue just an annoying noise. Toyota are a BIG culprit of pad shift. Only thing you can do is to take the caliper off the bracket and remove the pads. With the pads removed you'll want to put some sort of high temp grease on the ears of the pad (the part that inserts into the top and bottom of the caliper bracket) as well as the grooves. Try not to get grease on the rotor surface and if you do just wipe it of with a little brake clean. Put some grease as well as on the backing plates that contact the caliper/piston as well as some between the backing plate and the pad it's self. Reassemble and it should be quiet for about 6 months. After that the grease wears out or washes out and you'll have to repeat.

What causes pad shift is the minor play in all the hardware to allow the brakes to not seize or bind on itself. These tolerances can allow the pad to practically slide inside it's seat and the contact of the pad to the bracket as it slides 1/4" or less is what your hearing. Does it once in reverse backing up (seating the pads one way) then when braking in any forward motion shifts the pads the other way thus your clunk again.

As far as quieting while being hot, metal and everything expands with heat so the clearances may be less when heated up thus less or no noise.