So after a long road trip today in alot of traffic, and a constant annoying, embarrassing WOOT WOOT WOOT from the front right brake getting worse and worse as the trip went on, it was time to take things apart for the millionth time trying to solve this damn problem.

Also thinking that it might be the Hawk pads somehow, I picked up some Monroe Premium Performance Ceramics (it is hard as hell to find ceramic pads for the z32 calipers!)

So...took the caliper apart. All looked fine. No sign of rubbing that I could see, anywhere. rotors look good. calipers look good. pads look good.

I clean the caliper thoroughly and use some red nail polish to "mark" suspected/possible areas where the rotor or caliper could be rubbing. I re-lube everything, make sure shims and all are set.

Test drive. Sound still there.

Take the caliper back off and notice two things:

1. there is a slightly "polished" area on the top of the rotor, only on the inside. I could only see it with a bright light. In dimmer light it just looks like the rest of the rotor (rusty).

see:





2. Also there is a LITTLE TINY area on the caliper, right at the edge, where it looks like something could be rubbing. It's such a tiny spot I seriously doubted that it could be making the HUGE loud sound. But at this point I'm totally frustrated and willing to try anything. So I take the dremel to it and grind down the aluminum until the cordless dremel battery dies...I figure I shaved about 2mm off of it.

see:






3. THE NOISE GONE. I try every trick I can think of to make the noise happen, and I can't. This is awesome news!!!!!!!!!!!!!!!!!!!!


In addition, since my Hawks are pretty low after a year of hard driving, I say "what the hell" and throw on the Monroe Ceramic pads (no autocrosses soon, so I don't need the high-performance pads for the moment).

My thoughts on the pads:
1. They are very quiet. Coming to a stop, the Hawks make a little rumble. The Monroes are silent.
2. they are very smooth
3. initial bite is NOT nearly as good as the Hawks. It's still decent, but I'm so used to the instant bite.
4. after some hard braking, they don't seem to have any problems with fade, so that's good.

i'll probably use them for a while until I get around to picking up another set of hawks. At $70, the Monroes are not cheap, but they are worth it for someone who wants quiet, solid braking for everyday normal driving. They're pretty good.....

 

Note: I still plan to switch in the Iron calipers when they get here, for less flex during braking, but it appears the concerns about the aluminum calipers has been solved. I think the brackets just put it too close to the rotor, and when they both heat up and expand they just rub......

 

I have a similar problem, but for me it is the pad touching the top of the rotor, not the caliper. As you can see in my pics, I have plenty of clearence from the rotor(maybe too much which is why the pad isn't making full contact)
http://forums.maxima.org/showpost.ph...1&postcount=36

 

I had that much clearance too, which is why I never thought it could be touching there. I think that when the rotor/caliper warms up, they get closer together. It's that simple.

Highly suggest taking the dremel to the edge there. It might fix the problem for you too. And if not, it won't hurt anything......


btw, I get the pad overhang too, but if you look closely, it's not rubbing on the top of the rotor, it's just a skinny little "wall" there of pad material that will snap right off if you hit it with your thumb or something.

 

Yea I snapped it off once with my thumb thinking it was causing the noise haha. I will grind some away tomorrow and hopefully that fixes it

 

Irish, if you've taken your calipers apart a "million times" looking for the problem, how did you not notice the worn area on the caliper? The wear on the rotor is subtle, and understandably hard to detect, but the caliper wear seems pretty obvious. Am I missing something here?

Regardless, I'm glad you fixed your problem. Hope the never returns! Great info, and keep those lighter aluminum calipers!

 

Great job, Josh! I was about to start painting mine this weekend, maybe i should just grind it a little while before doing so.

Just to confirm, the area that you suggest grinding is the underside of the caliper, right? (e.g. the part that's about to touch the rotors in the 3rd and 4th photo that Kevlo posted).

Thanks!

 

wait a minute. are you saying that the rotor was rubbing inside the caliper on one side? why would that only happen during braking? your calipers might not be on too tight. i still suggest you try jeffs brackets. the design seems like a more secure setup

 

He already dropped a good bit of cash on some 2k4 2-piece rotors (that I couldn't find for the cobra, at least in blank variety), I wouldn't blame him if he stayed with that and looked elsewhere for a solution...

Good eye man. Glad we've finally figured this crap out.

 

I am about to do this, my noise has only been coming from the drivers side so I will do only the drivers side. If the noise does not come back I will do it to the pass side just for insurance.

 

So Irish might really be on to something.




I assume that is a spot where it rubbed because I KNOW I painted that with G2 caliper paint and that paint is NOT thin.


So me being too lazy to find my dremel bits, I busted out the handy dandy file.


I have not put them on yet because my arm/hand is tired as hell from using a worn out file on metal

I will have more pics of the rotor clearence to compare with my old pics linked above.

 

So it seems it has worked. I just got back from various styles of driving that used to cause the WOOT WOOT WOOT and it has not come back. I did make the noise come on the passenger side for a few seconds while turning around at a dead end street. Since I only did work on the drivers side(since that side was the loudest); this leads me to believe once I do the passenger side the noise will be completely gone.

I will not do the pass side till later tonight, it is MAD HOT right now

I really hope this fixes the problem.

 

Good job on solving the issue, I guess I avoided the problem by using the Z32 rotors. I can't belive I never though about it. Ash had to mod the stock calipers in that area when he made the early Cobra rotors setup for his Z32.

 

do any of you guys have grinding noise? i seem to have this under heavy braking coming to a stop. its usually heard when it hits 20mph heading for 0

 

It's prob from the pads/rotor combo.

 

Thanks for posting those pics! They just answered my question

 

because usually I'm working out front of my townhouse in the evening without good lighting. This time I was in my in-laws garage with a bright-*** worklight sitting 2 feet away.

 

no, it didn't happen during braking. Only when not braking. I still don't know "why" it was rubbing...but frankly as long as the problem goes away, I don't really care why.

BTW, people with Jeff's kit have had this problem too....

 

yup....now you can see why I didn't notice it the previous several times it happened....such a tiny little rub spot making such a loud-*** noise!

 

big things come in little packages. always remember that !

 

Glad it solved your problem. Still doesn't explain why I've seen that issue on stock brakes as well in both my 240 and Maxima and with my Wilwoods. But if it works for you guys, then great.

Make sure you don't file off too much metal and weaken the caliper. that's one of the points on the caliper where it gains/maintains much of its structural rigidity, so be wary of removing more than 1mm or so.

You would also think that after my driving on my brakes for 4 years, including heavy track use, that they would 'self-clearance' by now. rusty iron rotor on aluminum = file.

And no, Jeff's Cobra brackets aren't any more 'secure'. they're made of the same material, same thickness. the only difference is the offset on the cobra rotor doesn't require the offset bushings that are welded onto my brackets. In my case, those bushings are chrome-moly steel and cut by a machine shop within 0.001" of parallelism, so they're perfectly square with the bolt surfaces. might as well be a solid plate at that point. so there's no difference between the material or quality, only the overall shape and the rotor they're designed to fit.

The other fact of the matter is that there will be more pad overhang on Jeff's brackets. these calipers are designed around an 11" rotor, and the inside curvature of the caliper reflects that. putting them over a 12.6" rotor and clearancing them to fit as close as possible to the rotor without rubbing still shows just a tad of pad overhang. a 13" rotor will have even a small fraction more. immesurable without a micrometer, but pull out autoCAD and you'll be able to calculate it. This is not a problem with either setup unless it's a large percentage of the pad's friction surface. In the case of my brackets or Jeff's, the overhang is around 0.5% of the pad's surface area. not anything worth worrying about.