rustytoys

I just put new front rotors; my pads looked really good, so I left the old pads.

I now have vibration at high speeds when braking, and certain low speeds mostly with wheels turned.

The old rotors had worn a bit uneven, so I am assuming that could have caused the brake pads surface to be a bit uneven.

I know the rotors could be defective, but just wanted to throw out the pad idea because the rotors were pretty good quality, premium centric heavy duty.

Does anyone think the pads could be causing the vibration? And I guess that would go away once they wear flat on the new flat rotors if it is the pads right?

wyoming9

iTrader: (1)

Why would you install new rotors and not new pads??

What caused the old rotors to wear like they did?? That is the important question .

I have seen pads made of a compound so hard the pads wore the rotors down instead of the pad.

The old pads might not ever wear flat just heat the rotor because of less contact area .

Quite a few different things can cause vibration while braking.

Did you have this vibration with the old rotors??:jessica:

waskillywabbit

iTrader: (-1)

You replace pads and rotors together like peas and carrots.

:wabbit2:

Stevesk88

Who ever sold you the rotors should have recomended new pads as well. As a parts deadler i would have stressed that you get new pads as well. Its one of those things that you may as well do since your there already, no matter how much pad is left. The new pads will break in the rotor unlike your old pads that have seen heat and miles of braking already. I live where there are tons of hills and its up and down all day long in this country so i know a little about brakes haha

rustytoys

Well I had new pads, but the old pads were just not worn much lower than the new ones - and I knew they were factory toyota pads so I left them - I think they are about 2 years old.

The old rotors were not bad, no vibration, just bad enough that they could cause vibration from my experience; I usually just run my finger across and go by feel. Nothing really visually bad looking just looked old and had probably been resurfaced many times over 100k.

I have the option of going back and doing the pads I guess, I just wasn't sure if the old pads would eventually wear down to be even with the new rotors - although like you said maybe the pads would wear the rotor rather than the other way around...

But also, its not like the pads should be that grooved, like I said from experience the rotor was bad enough that I knew it could cause some vibration; but I have by far seen much worse, it was resurfaced probably 20k ago. So that is why I wonder if my new rotors are warped...

rustytoys

See, I don't quite understand what the difference would be once a few MM burns off either set of pads? Wouldn't what you call the "treated" part on the old pad be gone in a thousand miles?

rustytoys

It was my intention until I had the caliper off, then the laziness of leaving the pads overwhelmed me. I actually never thought about it though, the idea of the pad being grooved too... so now that I know that, definitely makes sense - at least for a few hundred miles?

kball

Vibration comes from uneven material on the rotors. You say you didn't have vibration before swapping rotors? I'm betting you have some dirt/rust etc... behind the new rotors causing them to wobble slightly. I'd take them off and clean the hub really good and see if the vibration goes away.

rustytoys

Yes, no vibration before - but I know from experience that there was enough of an uneven surface on the old rotor that vibration could happen pretty soon.

Yeah, that why I thought the rotors may be defective - unless the pads can cause vibration.

Problem is I wire brushed everything and spray painted it cause there was some rust, so I don't think there is anything throwing the rotors off; that said I need to just tear it back down and measure them for warpage I guess - so that will give me a chance to double check for debris there.

rustytoys

I actually just checked the old owners receipts, the old pads and rotors had 27K on them since a resurfacing and new pads. The pads are barely worn...

rustytoys

So I just tore everything down and did the pads; no rust behind rotors so that wasn't the issue; the old pads were factory toyota and only about 20% worn compared to the new ones. It needed some cleaning up anyway so good to do; we'll see if that helps...

Was also surprised to see the old pads covered in anti-squeek grease crap as they were done by Toyota last time; thought that wasn't required by Toyota? Is it up to the tech or something?

Kiroshu

NOTE: Brake pads most of the time are a harder material than the rotors.

Brake pads can cause vibration in rare cases, Flat spots, warpage, grooves.

Have you measured the rotors with a micrometer?

Checked for run-out? Run-out is not something you can see or feel it requires measurement and investigation.

Parallelism?

Dial indicator with rotor still on vehicles hub.... Checking run-out..

Replacing New rotors under old pads is like... Wiping before you poop...

ThatGuy1295

Brake pads are not "harder". Come on.... Steel brake pads??

skoti89

what kind of pads did you go with. Centric makes a great pad. So are napa's blue box and grey box, mid grade and premium. no rotor runs true zero, but we're talking in the thousandths of inches here. If you're replacing the pads, I always suggest to machine or replace the rotors. If you replace the rotors I'd always replace the pads. Like WabFab said, they go together like peas and carrots. If not I always tell my customers to spray the rotor with soapy water. Let it dry. It will help the new pad seat into that rotor properly. It's worked for years for me.

Also, a lot of places are selling cheap lightweight rotors. Basically throw away rotors. My NAPA rotors and Raybestos rotors I was able to machine a couple times before being below spec. just my .02

wyoming9

iTrader: (1)

I Have seen pads harder then rotors .

It is all in the compound the pad is made from.

I will now only use Toyota rotors as the Chinese have not quite got the heat treating down quite yet.

ThatGuy1295

They can't even spell quality. I won't use a china part no matter what.

DRCOFFEE

I'm not a fan of Centric rotors. Considering you have already used them, take them and get them cut on a lathe. I'd bet they came warped. Then while you are there buy some Wagner quietstop pads. Clean and quiet.

Don't be shocked if they warp again in a year.

Chickenman

if you replace the rotors and keep the pads you have to unidirectionally sand the pads to create a flat even surface. if you don't they could cause the rotors to wear just like the old ones you took off

ksti

Totaly agree with wyoming9 now a days being that brakes are asbestos free the compounds are a big factor and yes they are harder compounds. Old pad hardware can also cause a vibration. If your pads are not secured into calipers properly then that can cause a vibration. with the wheel on and weight of the vehicle on the ground that transforms into a squeak.

Replace it with oem brake pad hardware also. If your going to buy chinese rotors then plan on replacing them every brake job. I have toyota rotors on mine and when I did my last brake job I re-surfaced them. Used Toyota pads and its golden, no squeaks, no pedal pulsation.

rustytoys

I actually read about this so I tried it, but I totally misunderstood, thought they meant to spin the rotor and I couldn't hold it still enough! Just read a few help articles again and sounds like to just go around the rotor and check different spots, oops.