wow 1st post hi all i have a 2004 tl magna ls and ever since i replaced the front disks and pads with dba slotted rotors and bendix general ct pads (i think) i have been recieving a strange hum/high frequency vibration from the brakes under light and moderate braking application. i doubt very much this is normal, it doesn't seem to affect driveablity but any input you guys can give me would be much appreciated.

i would say either the discs and pads are still bedding in (depends on how long ago you replaced them-this should happen pretty quick in my experience) or the discs have been slightly warped by over torquing of the front wheel nuts. these cars are very sensitive to that and its a very common problem. they need to be torqued up correctly (90-110Nm,66-81 ftlb) or the front disc will warp easily. usually caused by a tyre shop using the rattle gun on them.

yeah i got the same setup on mine and it makes the same sound (kinda cool if ya ask me :))
did some research and it appears to be normal for slots

FYI: warped discs will cause either/and/or steering wheel judder/brake pedal pulsation/premature ABS operation.

yeah i got the same setup on mine and it makes the same sound (kinda cool if ya ask me :))
did some research and it appears to be normal for slots

FYI: warped discs will cause either/and/or steering wheel judder/brake pedal pulsation/premature ABS operation.

true, although it depends on how bad they are. i had an old trooper that had the same slight vibration, no pulsing or steering wheel feel. the discs were very slightly warped. cheers

Slotted rotors do hum when braking, doesn't matter what car they are fitted to. It is normal

Wow, I must be different as mine dont hum or squeal and I have DBA 4000 with Bendix C/T pads also.

did you put the thin metal inserts that sit behind the pad back in when you put it back together?

I've read that in theory slotted rotors "chatter" as each edge of the rotor contacts the edge of the pad as the slot passes over the pad. If this happens, I suppose it could cause a "hum".

I have fairly recently added RDA slotted front rotors to my KJ (I) Verada and TJ (II) Sports, can't say I've noticed anything but much improved braking - probably thanks in large part also to the QFM "HPX" pads which went in when the rotors went on. I suppose its been since about Mar/Apr that I added the slotteds, and haven't noticed noise shudder or any problems.

Is Normal
Do not worry.

Is Normal
Do not worry.

:stoopid:

I have a gen 3 2003 magna wagon.
I'v changed brakes on my cars and never had any problems.
But I took my brakes apart today and it's the first car that the rotors don't have the small locating screws on them to line them up on the hub, so when I took the wheel off the rotors could move!
Sorry to sound stupid, but Is this normal ?

Thanks Andrew