Wheel and brake pedal shake

ban25

I agree with all the comments here that it is likely due to deposits on the rotors. Try re-bedding. For street pads that aren't known to leave deposits, consider one of these options:

- Carbotech 1521
- Ferodo DS2500
- Project Mu

I also recommend staying away from drilled rotors, since they are prone to cracking. Blanks will be most affordable, and you can easily turn them if necessary.

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etx

So basically you guys are saying I didn't successfully bed in my brakes by doing 6 60 to 10 pulls??

SouthArk370Z

Not exactly. Deposits are, by far, the most common reason for your symptoms but you may be dealing with something else.

Bed as per manufacturer's recommendations (and season, too, if called for). For "normal" brakes/rotors, 2-4 runs is all it usually takes.

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etx

I just took it out and did 5 more after a set of three easier light stops to warm everything up. It's still just as bad, tons of judder.

I decided to put it up on jack stands and see if both wheels move freely. The passenger side front is nice and smooth when I spin it by hand. The driver side when pushed the same way stops within a quarter turn after I let go. Definately seems to stop too quickly to me, when compared to the passenger side.

Also I forgot about this part. I can hear a grumble noise coming from the front when driving at highway speeds and only when turning slightly right. When left I don't get the noise. May be related.

When bedding I did feel like it was going to the right slightly, but that could just be my perspective being on the driver side. The wheel didn't seem to pull and stayed straight.

I don't know what a wheel bearing going bad sounds like. In all my years I've never managed to destroy one.

SouthArk370Z

I think you can stop worrying about deposits on the rotors.

Sounds like it might be a wheel bearing. Pretty easy to check. Google is your friend.

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SouthArk370Z

A buddy of mine says the rotor may be out of square or the faces are not parallel. Ie, you got a bad one from the manufacturer.

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etx

Yeah, could be. Good thing I got them from Z1 and they offer zero freaking warranty.

I'm gonna put the dial indicator on the rotor and then the wheel bearing this weekend. At this point it's the only way to tell.

Worst comes to worst I'll turn the old rotors and give them a try.

JARblue

FWIW, you should baby it for a week or so whenever you change pad compounds (e.g. ceramic to metallic) because you want to get rid of the old pad material layer before bedding in the new pads. You don't want two layers of different materials on the rotor, which is what bedding different compound pads immediately will do.

Of course, as already pointed out, this isn't necessary for most street pads, which should be bed immediately

OP, if the dial indicator says the rotor is out, call up Z1 and explain that it appears as though you got bad rotor. Also ask them what the starting width is and check it against yours so you can demonstrate very little wear along with the mileage on them. Explain that you weren't able to bed properly due to the defect. They are very big in this community and if its a manufacturer defect, they should take care of you.

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stansens

Just a thought but I have seen rotors warp a week or two after replacement when the wheel lug nuts were not torqued to spec, or torqued in the incorrect sequence or brought to full torque in one pass rather than in stages. Impact guns are notorious for warping new rotors.

Spooler

6-60 to 10 stops. It took much more heat for my XP8's to bed in. I really had to get after them and get them hot. The first time I jumped on my brakes the car went left and right like crazy. It took a couple of time of that for that process to be completed. Then the casual drive around for 15-20min to cool them off. Did you torque your lug nuts down to the proper setting? I have always used 85ft/lb's on Nissans.

etx

Yep always use my old click type snap on torque wrench.

etx

Ok, dug into it last night.

On the driver side I checked the runout and found .020 on the rotor! Ouch! I removed the caliper and rotor, cleaned the hub with a scotch bright pad until it shined. Checked the wheel bearing as per the Timkin recommended process and found little to no play whatsoever. Turning by hand it is smooth and does not make any concerning noise.

I reinstalled the rotor, checked again. Got twenty thou again. I added marks at the highest and lowest points on the lateral runout. Removed the rotor and turned it on the hub by 90 degrees or as close to that as the lugs would allow. I checked again and still got 20 and the marks on the rotor still lined up so this tells me without a doubt the rotor is bad and the hub is fine.

Now I also moved the dial indicator to the other side of the rotor and checked it. I get the same amount of deflection on the inside of the rotor, also in the same direction. This tells me that the rotor is not straight, it is 'warped' as it it is not bulging. If the issue was pad deposits I would see a bulge, not a warp. Right?

I haven't tried the passenger side but it seems to be spinning freely so I'm focusing on the driver side right now. The driver side when free spun with the wheel on it seems to drag on the pad and slow down quite quickly.

RadioFlyer

I hear you, and generally I agree, but when you consider that if you bed in brakes incorrectly, you get deposits. So daily driving the pads on the street in an operating temp colder than they are designed for (even if the box says it's fine), would start to heat the pads, but not go through the whole "bedding" procedure, so it would leave deposits. Basically, the consensus on these pads are that as a daily driven pad, they start to heat up and act like they are bedding in again, but then since you're daily driving them, you are coming to a full stop, sitting at a light or whatever, and then cruising for a couple blocks, and then stopping again, and then shutting the car off. Without going through the whole heating/cooling cycle, you're just improperly bedding them. Which leaves deposits. I think it's a problem with the pads because there are plenty of other street/autox pads that don't do this.

Regardless, if you've tried numerous times to bed them, and the shake hasn't changed, then yes, it might be a manufacturing defect on the rotor. The odd thing is that you mentioned in your original post that when you first put on the rotors/pads that they didn't shake. That the shaking started after a week or so. If it was a manufacturing defect, you would have noticed the shaking right away. I've always bedded my pads by doing 10 stops in rapid succession from 60-5mph (not coming to a complete stop), and then immediately cruising on the freeway for 20 mins to fully cool them. If it still shakes after the cooling time, do it again. If the shaking still hasn't changed, then I guess it could be the rotor- but I've personally never seen an actual warped rotor, just ones with a lot of deposits. But if that's the case, do all of your same measurements, but get it on video and send it to Z1 as proof of a defect.

Another thing you could try would be to swap your pads from your left caliper to your right caliper, re-bed them and see if anything changes. Good luck!

etx

Ok well I rebuilt my driver side front akebono caliper and it seems to have fixed it!

Went out and did another bed in and the rotor is nice and dark now where last time it wasn't. I ordered up a wheel bearing to drop in and see if that fixes the weird noise when turning on the freeway. It seems to have a little more runout on the hub face than I like anyways.

etx

Another update. I replaced the driver side wheel bearing and the rotor now has 0 run-out. Also the roaring noise when I veer to the right on the freeway is gone.

Thanks everyone for all the input!