bg2128506

Looking back at the service history for my 2006 TL, I put these red W0133-1985388 Brembo front brake pads at the end of July 2015.
Quite shortly, my then current rotors with plenty of life left, warped (vibration while braking on a highway).
I purchased and put on Centric Slotted rotors (Power Slot 126.40062SL and R) at about the end of October 2015. I hoped slotted would dissipate heat more efficiently (and I stayed away from drilled).

Somewhere about this summer 2016 rotors warped again. Not so badly, but vibration was annoying. So I just replaced everything front with Centric pads and rotors. Vibration is gone; not so much stopping power / grabbing as with Brembo (and my front calipers are Brembo). I hope Centric will break in; it should as with any new pads.

Anyway, just wanted to give a word of warning. This is by no means scientific, but just in case you care to spare yourself from wasting time and money.

Cheers gang.

Turbonut

iTrader: (1)

You'll find that rotors don't warp. What occurs is that the pad material builds up
on the rotor surface and that creates the uneven surface and thus the pulsating.
If you have "hard" pads, you can install them, drive for a few days and the
pulsating will be gone.

bg2128506

Thanks, I'll keep the old rotors then; they are almost unworn.
What do you call a "hard" pad? Any particular pads reference?

BROlando

Correct that pulsations are almost never due to warped rotors. The culprit is pad deposits on the rotor. Sometimes also corrosion.

"wiping" rotors with cheap metallic pads is only kind of a short term solution in most cases. Try it, though.

My recommendations:
-Choose your brake PADS carefully.
-Buy blank rotors. I buy cheap rotors. Usually Centrics from Rockauto. They're just rotors.
-BED IN the pads. Manufacturers for street pads often don't put this recommendation in the box. Unfortunately, it's not because the pads don't need it. The pads DO need bedding.

Semi-metallic and Aramid type pads are better at preventing pulsation than common ceramic pads.

"Ceramic", and "metallic/semi-metallic" are obviously varying terms. What type of ceramic? What type of metal? Different materials have different characteristics.

The only good set of semi-metallic street pads I've used is the Hawk HPS (NOT the HP+). I'm sure others exist.

I don't really like street ceramics...but Akebono Performance Ceramics seem good overall.

Stoptech Sports are nice if you can find them for your application. They're an aramid compound. BUT....these are a street/track pad. So lifespan is short, dust is high, and they need re-bedding occasionally.

I will never buy a parts store branded pad ever again.

Turbonut

iTrader: (1)

I use a cheap set of metallic pads to clean the rotor on our '08 knock around car. Never had a problem
with the TL.
Here's some reading on the subject:
https://www.zeckhausen.com/catalog/i...Path=6446_6444

truonghthe

FIY proper bedding procedure prevent "warp rotor" by making sure the pad material got deposit evenly through out the entire rotor. Other thing you need to watch out is lug nut properly torqued technique and make sure your caliper piston doesn't froze from corrosion.

Turbonut

iTrader: (1)

I personally think the bedding in process is, shall I say ridiculous. Know producers recommend
the process, but I've never done it on the hundreds and hundreds of pad/rotors I've installed.
Think about the 17+ million new cars sold in '15, think they were bedded in? Ever see someone
take a new vehicle, pull out of the dealership and do the process, not that I'm aware of. Also,
there have been problems even when people do the process and then most reply that the process
was done incorrectly, and if done incorrectly, damage can be done to the components.
Save your pads & rotors and drive normal after installation.

thisaznboi88

iTrader: (7)

^ but its fun to drive like an idiot and smoke the brakes

truonghthe

I never bed my new brakes in but at the same time I do not abuse it. Just normal stop and go will do.

GreenSpades

I always attempt to bed my brakes. I have also had the "warped rotor" feel. I have one time successfully gotten rid of it by rebedding them and one time by them just getting better over time. Make of that what you will, just my experience. 8 out of 10 brake pad jobs ive done have been perfectly fine for the next 50,000 miles or however long they last.

I dont think you need to worry about brake bedding procedures on a new car because I think they have already taken care of that to an extent in the factory and pre dealer preperations.

Turbonut

iTrader: (1)

Really believe that the factory or dealership beds in the brakes on a new car?
Like they say, I've got the Brooklyn Bridge up for sale.

vietxquangstah

iTrader: (7)

Techs at dealerships do not take cars out to bed in brake pads for new vehicles. They don't even bed in the brake pads after doing a complete brake job. Just a short test drive testing the brakes at various speeds.

GreenSpades

That's not what I said.

GreenSpades

That, also, is not what I said.

GreenSpades

Maybe I worded that poorly for you guys, but my point was you dont need to worry about it. What I said was PRE dealer and at the factory. Dealerships dont do anything except take your money and give you the car.

Turbonut

iTrader: (1)

Doesn't really matter as neither the dealership nor the factory bed in brakes.

t-rd

You need to bed in the pads if they are semi-metallic, this transfers a layer of pad material onto the rotors for a better grabbing feel. Just find an open stretch of road late at night, speed up to at least 45, then brake hard down to 10 without stopping. Do this at least 10 time until you see the pads/rotors smoking. You'll be surprised how great the pedal feels after that. There is a huge brake feel difference between using ceramic/organic pads and semi-metallic pads. I will not go back to ceramic/organic pads even though semi-metallic pads dust like crazy.

I have not "warped" a set of rotors since many years ago when I discovered that you need to pay special attention to the wheel hub surface, brake pad retaining hardware, and calipers' slider pins. So I think you are not doing something correctly:
- You need to absolutely clean the wheel hub's surface before you mount the new rotors. The slightest amount of rust build-up on the hub transfers to a large difference when moved out to the hub
- You need to smear lube in the brake caliper bracket's pad retaining slots to prevent rust build-up from pinching the pads over time. This is the most obvious culprit of upper or lower portion of the pad moving in and out unevenly, which also causes a pulsating sensation.
- Always use new brake pad retaining hardware when installing new rotors and pads
- You need to re-lube the slider pins with silicone paste and replace the dust boots if necessary. Rust build-up around the inner edge between the boot and the caliper bracket can lead to the slider pins not moving in and out freely.

Lastly, you should re-lube slider pins and and clean brake pad retaining hardware every 6 months, this helps tremendously in keeping everything in good working order. I have not had a single brake related issue in 3 years.

Scottwax

My mountain bike has hydraulic disc brakes and I was told by the bike shop to properly bed them. Like a car? Yeah, like a car.

bg2128506

Ok, I did some bedding in today (following the idea "pre-heat-then-really-do-it"): pre-heat with some breaking, then did downhill alternating braking up to the point of getting pads' smoke. Rotors look evenly burned/tanned.

Thanks everyone for the useful info/insights - warped rotors did sound not right to me as well.

WDPanda

Maybe factory pads are scorched.

bg2128506

With the new rotors, the vibration gradually developed back. When it was not too bad, I put on very basic semi-metalic pads, which did not solve the problem at all. So it was not the residue.
The vibration is now super bad (on relatively new rotors) to the point it affects the braking efficiency.

On the other note, I had that sound as I identified as coming from the axle's inner cv-joint (started as soon as I replaced the axle). As the axle was after market, I put few weeks ago Acura OEM axle. Most of the noise is gone, but not entirely. Now, with the vibration during the braking, there is a clunking or rattling sound as if it was coming from the brakes (I would say caliper's not tight or rotor's dust cover makes this sound - but both are fine).

Now I am blaming the lower control arm compliance bushing, which seems not in a good shape. May be it's in a bad shape, hence the noise while braking and that strong vibration. So I'll try to replace it.

There is another possible reason. I was going to clean and lube right front caliper. I did pushed the pedal without brake pads or a wooden block inside of caliper, so one piston slide out (and braking fluid started to come out). As I was trying to figure out how to put the piston back in (the dust boot was still in), I noticed the dust boot had some tear. May be a time to replace to boots / o-rings as perhaps some pistons do not come out / return back freely.

horseshoez

iTrader: (2)

I'm thinking your best bet would be to put remanufactured calipers on your car; RockAuto is currently selling the Brembo units for under $50 per side.

bg2128506

Re: caliper, I put the caliper piston back in and will just need to replace the dust boot. Overall, all pistons seem fine, sliding in just by hands.

I still have the previous set of Centric slotted rotors (barely few months old), which I assumed got wrapper. I replaced them few months ago with Centric non-slotted, which now vibrate badly. So yesterday I put the left-side slotted rotor on instead of right non-slotted just to find out if my rotors go bad on one side only (which ~ rattles).

It's much better now although the vibration not completely gone. So the net result is: either left side rotors also go bad or there is something in the right front suspension which is not related to braking, which creates the vibration.

Upon further inspection, the compliance bushings are good on both side so I will not be replacing those.

Also, I now started to tighten the wheel nut by spec (79 lbs/ft). Too late but still.

My game plan is:
- as I have two sets of rotors, I will get one set machined, then I will put on the rotors one side at a time, starting from the right side, to find out if it takes one or two replaced to fix the problem;
- will tighten the wheels by spec from now on;
- also will replace the dust boot, although not so really important.

bg2128506

UPDATE:
I put the second (previously used and also developed the vibration) slotted rotor on the driver's side (I mention these rotors in the beginning of the thread).
So now I have: left-marked rotor on the right and right-marked on the left (I don't think that matters), previously used and vibrated.

I tightened the left wheel nuts by spec (~79lbs/ft), so both wheels are tightened by spec now. Pretty much the first time in my life on any car I ever owned.

The vibration is not there. There is a slight hint of vibration when braking from 70mph, but I will wait and see if current semi-metallic pads remove the possible residue from the rotors.

I will keep this thread updated.

BROlando

Slot direction absolutely matters for functionality. They're marked left and right for a reason.

This is the 1st time you torqued lug nuts (??!?!?)

thoiboi

I'm glad I wasn't the only one that caught that...


That may explain the warping rotors

t-rd

Torquing lug nuts evenly is the first thing you should do to prevent a rotor from seating unevenly on the hub. Even the slightest and tiniest difference in height when rotor sits on the surface of the hub face, will cause a huge runout / wobble when moved out toward the wheel. Did you also read what I said above about cleaning the hub's face? You need to absolutely make sure the hub's surface is free of rust. Even the thinnest layer of rust will cause vibration. You don't have a rotor problem, you have technical issues and small details you haven't followed.

thoiboi

At least now the mystery is solved..... after 6 months

bg2128506

Slot direction matters indeed (i.e. consider how centrifugal force affects buildup / particles travel based on slot's angle) for the top performance. I don't believe though it absolutely matters from mechanical engineering or structural integrity point of view.

I am planning to run them switched for some time to get wear out any pattern developed on the opposite wheel, then switch back to normal.

bg2128506

No, I missed that. Will clean the hubs indeed. Not so much rust in California though; dirt - yes.

truonghthe

Slot direction is not matter unless the cooling vane is curved and ONLY curved cooling vane then you will have to mount properly, check video on Youtube where Stoptech explain if the slots pattern mounting matter. FIY this is why XLR8 Azine package has sticker label L and R.

Si_jeff

Vibration is caused by friction material deposits that get baked on the rotors. Best is to use an aggressive brake pads preferable with a GG friction rating, to smooth out the surface of the rotor.

nfnsquared

^^^^^^^ WRONG, WRONG, and WRONG.

^^^^^ THIS!!!! Bolded is my added informationl

bg2128506

I did put the aggressive semi-metalic pads when last rotors started to vibrate. I ran them closer to 2 months, but things only got worse.

• The first take away - the rough pads don't help when it's not related to having deposits on the rotors' surface;
• The second take away - I went to the shop today to get those rotors machined. The mechanic looked up the specs, inspected the surface, measured the thickness and said he need to machine X-deep to remove those blue heat marks, in which case the rotors would be beyond min service limit. So, the blue heat marks (on the most of the rotor's surface), very significant vibration - rotors do get warped (or you name it - not related to deposits).

thoiboi

I was referring to torquing of lug nuts.

Jackass

Blue heat marks? What are you doing to get them that hot? Pretty sure any car I have ever had, my rotors were either shiny or rusted....never blue from heat. Do you have a dragging/stuck caliper? My '05 with Brembos have yet to ever have any kind of pulsing issues in the 125k miles I have owned it.

horseshoez

iTrader: (2)

The blue heat marks brings me back full-circle to an effed up caliper or two.

Si_jeff

Strongly disagree, blue heat marks = brake pad deposits. It's simple logic , really. If you use aggressive enough pads, like Hawk's, Akebono Sport Ceramic , you will never have any blue heat marks. your roars will be shiny all the time. Unless you put a cheap rotors that may easily warp. Lots of crappy rotors out there nowadays specially since they are all made in China.

bg2128506

I don't really see any simple logic. My slotted rotors got wrapped under Akebono Ceramic. Now, btw, I am continuing with cheap semi-metalic for some many months, not getting any worse, in fact improved a bit, but still wrapped as they vibrate at braking from above 30mph. I would think that the deposits should have gone by now long time ago (== blue heat marks), but blue heat marks are here not any fainter.

DMZ

Now ya got it! Improperly (OVER) tightened lug nuts are the chief cause of warped rotors on these cars. Just letting the impact gun do the tightening is big a no no! 80 ft-lbs is exactly the right spec for all Hondas and Acuras!

I use the Wagner MX1049 pads. More than adequate stopping power with none of the dust, short life, or insane pricing of the OEM pads, and at a great price too from rockauto.
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