I had posted a question a while back on what the knocking sound would be when braking hard (not foot through the floor hard, but hard). The responses I received were very good and I am grateful for the feedback. I have not been satisfied with the answers though, because I can't imagine a vehicle of this quality having such a nasty noise coming out of it while doing a very normal thing like braking. The feedback I received was "It's probably the ABS Actuator" and "It's pretty loud in the Z32". I took it to the Nissan dealer and he told me the same thing. Again, I could not let it rest, so I took the car to a local auto repair guy "Lemon-Aid auto" (if you can believe that). The mechanic told me it was the brake pads following the groves in my brand new "Power Slot" rotors. he said the texture of the rotors were that of a record and that the brake pads would folow the groves to the middle of the rotor and then SLAM! back in place. it would happen over and over while braking hard "SLIDE... SLAM!!, SLIDE...SLAM" which is what sounded like KNOCKING to me. Well, I am pretty frustrated with the notion of $500 rotors causing problems, but am anxious to hear what fellow Z owners have to say about Lemon-aid automechanics point. he told me I will need to have the rotors machined to remove the groves, but I am reluctant to do so because I can't imagine them putting the groves on there by mistake.

Any thoughts???

btw, these are all brand new rotors with brand new Hawk pads.

 

sounds like warping.

just a thought, what direction are the slots facing?
try swapping the rotors over to the opposite side of the car, might make a difference as the slots would then spin in the opposite direction.

 

i assume they made slotted rotars for a reason. ive been in many cars with slotted rotors...never happened... what brand are yours though mabye soem guys have heard bad stuff about your brand...for all i can say is ive never been in a car that did that from slotted rotors....never been in a Z with slotted rotors though so i suppose it could be a different story....some how

EDIT: jsut saw Rizz's he said they are brand new so i hope they arent warped...facing the wrong way mabye...they are directional last time i checked they should be labeled or something of the sort (instructions saying witch way they face... etc.)

 

I do not believe it's the slots... it's actually the tiny ribs like that of a vinyl record... if you drag your fingernail across the face of it it's like little ribs. The slots are facing the correct way, as instructed and as other photo instructions I have seen on these forums. Does the vinyl record analogy work for you?

 

Check your kingpin. The kingpin on my last Z was bad, caused knocking under low speed breaking.

By the way, your slotted rotors aren't helping your breaking system at all. I hope you know they're purely cosmetic.

 

My slotted rotors caused a slight knocking sound when they were new, it diminished greatly after a couple of weeks.

https://www.zdriver.com/forums/showp...3&postcount=20