i always had very large ammouts of vibrations when i braked from 50+, so i decided to switch rotors and put new pads. i got front 2k1 Slotted/dimpled Brembo rotors with Ulitmate Metal Axxis pads.

the werid thing is, after i left the shop, i braked from 30mph and i heard a humming and a little bit of pulsation. then i went to the highway and i pressed the brakes going like 60 and the steering wheel shook like i didnt even replace the brakes, i was starting to think what could it be.

i drove for another 15-20 minutes, braked hard and the noise got even worse, then i parked the car for about 10 min, drove around and it was much more quieter, then i went to a short strip, hit 85 and braked, the steering wheel didnt move an inch and everythign was smooth. then i went like 35-40, braked hard and no pulsation, just a humming noise(which i dont understand why)

i was suprised but then i said oh well , as long as they are ok, i dont care lol. the question i have is, shouldnt i break in the brakes a little bit before i brake hard?, i rememberd how they said in the break in period to not brake hard, so i thought maybe it have something to do with new pads and rotors, is this right? and the humming, is it because of the new pads and rotors?

thanks and sorry for the long post

 

I believe that every time you change the brakes (pads or rotors) you should break them in without braking hard. I don't have cross drilled or slotted rotors but I would imagine that it would be the same.

 

The humming noise you were hearing is probably from the slotted rotors. I put slotted rotors on my Accord and they used to make that noise too. I beleive it is from the air going through the slots when you brake.

Also, the vibration was probably because the brakes weren't properly set in the calipers yet. You need to do a few hard stops before they will be adjusted. The shop probably didn't quite do as many hard stops as they should have before giving you your car back.

Either way, nothing to worry about.

 

so i can basicly brake as hard as i want to?

 

Actually, there was a thread running a few months ago about breaking in brakes. It had an article from what seemed like a reputable source, that said you should do hard stops from 60 - 5 mph a few times, to evenly coat the rotor with brake pad material. Trouble is, the coating wears off in "normal" driving (stays on with continued race driving), so I didn't bother doing it (the local authorities take a dim view of "race" driving on the street... ).

Hopefully someone else can point you toward it - I can only remember a few details, but will try a search.

>>>>>>>>>>>>EDIT: Ah - didn't find the exact post, but did find this cool link which discusses bedding pads, seasoning rotors etc.

http://www.baer.com/Support/TechTips.aspx?TechTipID=5

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Did you get your slotted/dimpled rotors from Tirerack? I will probably get those eventually.
Got pics of them on your car?

J.

 

nope, i got them from the GD on Brembos...its in the GD forum.

btw, did anyone ever heard of ultimate metal axxis pads?, are they better then the normal metal axxis?