Metallic Clunking When braking...
 

I need some help diagnosing a bothersome "hopefully not safety related" metallic clunk when I'm braking, and I only hear it on braking. Noise is coming from the front, (maybe left side?). The sound is more evident when I'm gently stopping from a roll, not every time, but like every other time.

A few weeks back I've replaced pretty much the whole braking system on the Vert: lines, pads, rotors. I even got the master cylinder replaced just two days ago. When I bled the front left, I've noticed the wheel's inside hub to be a bit "chatter'ed" with some light grooving. I spun the rotor and it looks like the rotor isn't spinning in a "perfect" circle around the hub.

Could this be a wheel bearing issue, or a hub issue with my front right wheel? Or are there other areas of interest to inspect/check. Or do I need to check my work on the pads/rotors in that area again?

Kinda frustrating when you're in the driver's seat and trying to diagnose a sound from the front, when braking. :banghead: Thanks!

if the rotor was not spinning true I would suggest either the rotor is not sitting flush on the hub (build up on the hub that was not cleaned off properly before installation of the new disc)
Otherwise it is possible you have bad wheel bearings.

Do you have any pic of the "grooving" I mean you say the "wheels" inside hub.. I guess I don't understand what part u are talking about.

Warped rotor maybe?

Rotors are brand new off Tirerack.. Brembo blanks. I'll try to get some pictures tomorrow inside of that front wheel, I have to clean/paint the rotor hats anyways. They're rusting already! That's why everyone needs a daily when owning 7's.

Maybe I'll rotate the wheels/tires and see if I get the same clunking.

Just because you have new rotors do not mean the rotor is TRUE..

it is possible to buy a new rotor that is warped.

Actually I am guessing that you have an s4 lower control arm. The bolts in them get loose and then you get that noise, certain bumps will also set it off. The s5 ones are on piece and do not do that.

The Vert is an S5, but I will check that area again.

Is it just one clunk and do you hear it over bumps?

sounds like an endlink or sway bar bushing, check to see if you can giggle it, its the sway bar has play around the bushing it will move and clunk when braking since the inertia "pushes" it forward towards the metal bushing holder thingy.

Well... I was cleaning my rotor hats this weekend and snapped these pics. Looks like my hub or wheel is off causing these marks right? Check out these pics:

http://www.rotarycarclub.com/rotary_...1&d=1228769468

http://www.rotarycarclub.com/rotary_...1&d=1228769468

The clunking happens usually from slow braking, otherwise I can't hear it. It's intermittent, but I would say >90% of the time. From the pics above, it seems somethings not right with the wheel hub [obviously]? Before I go run out and start buying every used part around that area, what's causing that chatter? Unbalanced wheel? *shrugs*? TIA.

Stock or aftermarket wheels?

Checked wheel bearings for play already i assume?

Stock Vert meshies.

did you properly torque your lugnuts?

well... no... but I will do that today and see if it gets rid of that noise.

Any other ideas folks?

Yea check the screws on your brake rotors. I had one that came loose and it caused some strange clunking noises. I was suprised since I would have thought the lug nuts would have held it tight.

I never put the screws back on when I did my brakes- they are more of a source of trouble IMO than anything. If anybody has experience to the contrary, feel free to let me know. :seeya:

I've heard stories from people that didn't torque their lug nuts and suffered the consequences. IMO it is a simple thing to remedy and not a bad habit to check the torque on them every so often.

Frizen, I thought the same thing. Torque the wheels and the should be held tight. But I have the screws in ther and it started to back out and the rotor would make that noise like it was loose. Checked and re-checked the torque on the lug nuts. Only went away when i tighted up those screws. Noise went away and well that was all I did.

Torque those nuts to 90lbs.

Note: The noise was not present when I tried to replicate it today, turned the car on, no noise when the car/brakes are cold... Bro in law, suggested we take a closer look at the wheel bearings/hub assembly.

On that note, anyone have a spare 5 lug hub assembly lying around?

they are impossible to get off unless you have a impact hammer or whatever its called.

Yea, had to use that to get mine out, put anti-seize to try to keep them from doing that again, but with all the heat that goes throught there it will be a matter of time before you need that impact screwdriver to back tham out.

try using some PBC grease or anti-seiz to lube the caliper slides and the back and ends of the pads....ive had that take care of the same noise before...also make sure that the springs aren't binding

I used allen head screws so I wall have more leverage when I do mine again.

I probably would not use Anti-seize when there is specific brake pad stuff out there for super cheap. Besides...if any of that anti seize gets on your brakes or rotors your royally pwned.

I use the Allen head screws from fastenal myself. (I do have access to an impact screwdriver, but it only rings the bolts off in the hub and you have to clock the rotor differently next time.)

I found my clunk problem by jacking the car up and dropping it while watching the suspension (mine also clunked when going over bumps at low speeds).

If you could have somone walk beside you with a flashlight and watch if anything moved as you moved slowly and then braked it could help you a lot.

(The front calipers have no slides that I am aware of, so I doubt it is that).

I got mine from sears for about 10 or 20 dollars with a couple different bit attachments.

I used to hate allen head and torx bits but I own an audi right now and the VW Germans love to use them so I picked up some torx and allen 3/8"s drive socket sets for them, got one new for a decent amount and the the other at a garage sale for 3 dollars!

I now have an extra set of front hubs to swap out. Thanks to Hector who was parting out a TII! Just need some new bearings from Mazdatrix next week and we'll see if I get rid of this noise.

http://rotarycarclub.com/rotary_foru...1&d=1229834210

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