SQuaLZ

Hey all. So now that I have my Ram along with my Ducati, the Z gets no love. Yesterday was the first day I drove it since last year, and as expected, the rotors had some surface rust.

Figured a few low speed stops would take it right off. Fast forward 20-30 miles later, the majority of the rust is off, but I am still getting crazy vibration under braking.

The brakes, both front and back, have under 2,000 miles on them, and I'm really hoping I don't have to replace them. The front rotors are Stoptech slotted on the Akebono BBK, while the rears are OEM nissan rotors. Running Hawk HPS pads on all 4 corners.

Any ideas? Right now the only thing I can think of is just continuing to drive it and hopefully it gets better. Or maybe remove the wheels and spray the $hit out of them with brake cleaner.

Never had a car sit for that long, so this is new territory for me.

Atreyu'z 350

Hey Squalz.. It almost sounds like a seized caliper, but you say it's only under braking.. Are any of the wheels warmer than the others after a drive? Do you smell that typical burning brake pad smell? Regardless, I would get it in the air and spin each wheel and feel/listen for abnormalities. If you find the odd-ball I'd pull that wheel and inspect/clean, if no odd-ball, I'd pull all of the wheels and inspect/clean.. Could just be some rust in a place it's not supposed to be.

SQuaLZ

The first mile the car was squeaking the entire time, but yea the vibration was only under braking. No smell, wheels spun fine when it had it in the air yesterday. The car is driving fine besides the vibration under braking. Yea you could be right, maybe the rust buildup got stuck or something. Going to have to put it in the air again.

iideadeyeii

iTrader: (6)

I NEVER get vibration from rusty rotors. My cars always sit for long periods of time an collect rust on the rotors.
I would take it apart and check the pins, you can always pull the rotors and hit them with a wire wheel on a grinder(or a drill, but it takes longer)

jhc

Maybe use the e brake to rule out front versus rear. A bench grinder with a steel wire brush (or drill) will reduce the rust. Glazed/contaminated pads also possible.
Good luck!

dkmura

iTrader: (64)

Pad buildup on race rotors usually has me scrambling to find some #200 grit to work out any high spots. Might work with heavy rust as well.

SQuaLZ

Thanks for the help guys. I will check next weekend. It is tough to find time to do anything during tax season.

JMII

Check the pads. I had the Akebono / Hawk combo and the pads do not fit the rotors properly, they overhang slightly. In my case they just squealed like crazy, with only a slight vibration. CZP actually makes a product that claims to "fix" this problem: https://conceptzperformance.com/czp-...-h_p_28909.php ...well I fixed it myself by never buying Hawk pads again. Back to EBC for me.

SQuaLZ

This is interesting... Maybe that's why it was such a PITA to install the pins with the Hawk Pads.

Never had vibration issues before this though, but I might just switch the pins when I look.

Thanks!

MicVelo

Long shots:

- Sticking pads from sitting and building up crud notably on the pads? Semi-metallics and full metallics can do this. (Even here in temperate CA, I've had some sticky pads from sitting for extended periods.) As dkmura mentioned, maybe hit both pads and rotors with some 200 grit followed by Brakleen as you mentioned.

- Car sitting outside in the cold? Possibly warped rotors (although this is an extreme long shot and I would hope not).

- Flat spotted tires from underinflation? I know this seems pretty stretch too since the condition is only under braking; but y'never know.

Good luck on this!

CK_32

iTrader: (1)

Well maybe if they weren’t all broke all the time


But yea my rotors rust even if I leave it for a week. Usually 10 minutes of driving works it right off. All I hear is the soft rub of the rust dust and feel a tiny bit less brake traction. But once it’s gone it’s back to normal. No vibration.

Sounds more like you have pitting warped pads/rotors.

kham25

iTrader: (3)

I have the same problem. Brembo with Stoptech slotted rotors & hawks pads. If my car sits for a week I have the vibration issue however I've noticed hard braking from 60mph to 20MPH few times clears it up.

The embrassing loud squeal reversing out of my driveway is another issue I have to live with. Stock 07 OEM brake never had any of these issues

zakmartin

Yank the calipers apart, wipe off and add fresh high temp silicone grease to the caliper pins. Pull off the rotors, take them outside and freshen them up with some 3M Scotch-Brite Roloc Surface Conditioning Discs (07480) attached to a drill. You can do the same (gently) with the pads. Put everything back together and clean up the mess with brake cleaner, a nylon brush, some dry shop towels and a drip pan.

Have someone push on the brakes and test all four corners to make sure the caliper pistons aren't frozen. Also check your e-brake, add a dollop of grease on the contact points (not the shoes) and make sure they're adjusted properly.

If it's been a while since you've changed out your brake fluid, now would be a good time to do a flush with a positive-pressure flush kit. If you live in the rust belt, good luck with your bleeder screw. Some people have reported good results using one of [ ,] but you'll need shop air and an air hammer:

SQuaLZ

Is brake cleaner safe for the Akebono calipers? I don't want to ruin the finish of the calipers.

JMII

This is how I learned the Hawk pads where causing my issues. I thought they were sticking on the pins. When I pulled the pads the overlap was noticeable. Here is picture of what I found:
https://my350z.com/forum/brakes-and-...l#post10908738

No problem I've blasted mine pretty good several times. They are the factory Infiniti silver colored ones. Not sure about other paint colors or finishes.

Atreyu'z 350

I wouldn't recommend it, for it can fade the paint or powder coat. For light brake dust use simple green or the like and a soft toothbrush. For heavier jobs use a good quality mag wheel cleaner and a soft toothbrush.

Atreyu'z 350

Oh wow. OK then.. I guess the brake cleaner we have here in PA come standard with sulfuric acid.

zakmartin

You can use chlorine-free brake cleaner if you have concerns about it affecting the finish on your calipers.

SQuaLZ

Ordered the pins from CZP. So once those come in, I will take everything apart.

I appreciate all the help!