acarapella

Ok,

I installed centric coated rotors and ceramic pads all the way around in December 2017 20,000 miles ago. Somewhere in the middle, they started to pulsate. this was NOT my first rodeo... probably my 20th brake job but the first with problems. As always, I cleaned everything, even sanded the area the hardware sits so the rust didn't squeeze the pad tabs and stop them from sliding. Took my time, and did the job confident that the car wont need brakes for 80,000. WRONG. After fighting with centric for a while, a met their lead engineer and he taught me the first new thing i've learned about brakes in years: he said "did you measure initial run out with a dial indicator?" of course I though he was nuts at first but it made sense. Cleaning the hub well almost guarantees the rotor will turn true if it itself isnt out of shape of the hub isnt bent. there should be no more than 0.0002" of run out. If there is, mark high spot and corresponding lug, turn it close to 180 (impossible with 5 lugs of course) and see if the high spot is on the same side... if so its the rotor if it flips 180 (or as close as 5 lugs can be) its the hub.

I measured and found perfection in the first three wheels, and then 0.0012" on the fourth. CRAZY! it was the hub.I replaced that hub and the bearing as they cant be saved. Tried using the old rotor, still feeling something but not in the wheel, only my foot. I replaced that rotor (just one was ok per the engineer who taught me all this so I am good with it). I still get an intermittent shake in the peal and floorboard, passenger can feel it, once down to about 30mph and to a stop. It does NOT feel like a rotor issue. Nothing in the front end feels loose. I am at a total loss. I have less than 30% of the allowed run out in all 4 wheels, its not rotors. Open to suggestions

I also hope the above taught people something. At the very least, make sure your hubs shine when doing a brake job, also make the rotor/lug position when removing a rotor for other work. get a dial indicator. According to this engineer, it can take up to 5,000 miles to feel a pulsation from run out that was present when the rotors were installed brand new.

wmj259

I also had centric rotors installed a year back (may17'). So far I have had to get them machined twice because of warping.

99custom

I just put on premium centric coated rotors about 5k miles ago on my 02 ES300, so far so good. I hope they don't warp since I've never had an issue with centric rotors.

acarapella

acarapella

I really hope you all can help me solve this. The suspension seems tight. I DID discover that my front driver and rear passenger calipers have at least 0.125 if not 0.25 of play in them, not the brackets with the 17mm bolts but the actual sliding caliper. the movement in is every direction except in an out (as they would move when I stop) its up, down, and side to side on the X and Y axis if looking at it (Z axis would be on the pins as intended to work) could the be causing the hopping/egg-shaped-tire feeling when braking?

acarapella

acarapella

Ok... reluctant to come back to this post as I'm the only one talking.... pulled the front brakes apart toady prepared to damage cracked pads if they were, and they weren't, but I did discover on one side, the bottom pin was so stuck I needed a prybar and a hammer to get it out. ALong with it came a shredded bushing (the little black rubber band on the lower pin). The sims were also shifted and mangled, so I took them off and cleaned the back of the pads, greased them well and put it all back together (after scuffing the pads). Seems way better but I've had the issue go away and come back before.

Oh, and I replaced the pin bushing with three O-rings of the same thickness that, when side by side, made up the same width. We'll see tomorrow....

Hayk

iTrader: (1)

Stuck pins would definitely do that. Keep in mind that if the pin was stuck for a while your pads may have already been worn unevenly and will continue to cause a vibration. Did you compare them side by side to see if they are wearing evenly?

I can undnerstand what you mean about throwing your car up on Craigslist. Sometimes I feel the same way with the vibration I've yet to pinpoint.

RXGS

iTrader: (2)

Rotors are so cheap, why don't you just replace them?

acarapella

It was the shims on the pads. They were loose, and the back of the pads rusty. The shims are removed, the backs of the pads cleaned and greased, and all seems well. I have never had this much trouble with brakes... not on all the other 22-23 cars and 500,000 miles I've worked on my own cars, but I think I am in the clear.

And the rotors I purchased are electroplated, good rotors. They also show less than 0.0005" of runout, or roughly one quarter of what lexus allows per their service manual, why replace?

RXGS

iTrader: (2)

Hayk

iTrader: (1)

You know I've yet to have my rotors/pads last until the backing plate. I've been replacing them every 2-3 years based on rust, vibration, or uneven wear. Some of it was due to sticky caliper pins, but this year I learned about the importance of lateral runout including everything you mentioned in your post.
I've also heard that uneven/excessive lug nut torque can mess up the rotor runout and cause your rotors to wear unevenly. I've been staying on top of lug nut torque, slider pins, and replaced all my calipers. I've yet to accurately measure the runout.
Bought my own gauge, but can't figure out how to get a good reading. The other day I was trying to measure my runout on the hub and rotor. The gauge cover popped off and messed up the needles, so now it doesn't work as well. I'm gonna ask a shop to measure the runout to see what's up. Maybe it'll also explain the high speed vibrations I've been having.

p.s. I also put Centric Premium rotors all around with Akebono pads. All new calipers from A1 Cardone.

acarapella

RXGS I am in Churchville, 17 miles out of Rochester on the Buffalo side. The salt is brutal. I am OCD about my cars, so I dont bother with a winter beater as I would just be OCD about that, too which would be a headache. I was going to undercoat my car this year rather than wash it every couple days like in the past... that seems to fail at keeping hardware from rusting


MrBooby, yes, and this is a very sad thing. Its just the way it is when factors other than the rotors and pads themselves can cause issues therein. Lateral runout on a rotor is tough. Supposedly you need these special cones that distribute the lug nut force on more of the rotor than just the holes, same way the rim would. I skipped that and just went slightly beyond hand tight with 3 lug nuts. I can see how MY way would cause a false positive, that is, show runout falsely that doesn't actually exist, but I seriously doubt the opposite, where my method somehow misaligns the rotor into the EXACT position it would show zero runout ON ALL 4 ROTORS. Just extremely improbable.


General motors, who unlike Toyota with their just-on-time production process and employees incentivized to identify and overcome issues, used hubs with issues on a couple million cars. Their dealers were instructed to use said cones to measure run out in new or recently re-machined rotors, and correct whatever runout they found with shims. We all know that runout in a perfect rotor is from the HUB, which apparently was common and accepted on their cars. Every Toyota I have been blessed to have around the 80,000 - 100,000 k mark had its original brakes. I can go on for paragraphs on how great the TPS (Toyota production system) is, but I'd be preaching to the choir (even if they dont know, but their 200,000 mile cars do).

This has sucked. I hope its behind me, as each of the half dozen times I pulled these apart to investigate, they were fine for a hundred miles after. THe biggest improvement was first getting rid of the bent hub, then figuring out the passenger side shims were the issue. Driver did the same thing a week later. I hope this is resolved.

Lastly, high end aftermarket rotors with factory pads is a winning combination, but Toyota pads are expensive, and as mr. booby pointed out, seems impossible to get a full run out of brakes once a car has 100,000 miles of issues in other places, especially a northern car. Who made Toyota's pads?