TBA

Car went in for an oil change and tire rotation today. I noticed there's a vibration when braking to asked them to check if the rotors are warped. Car has 34k miles.

The shop said yes, they are a little warped. But the only way to fix it is to do a brake job and replace the rotors. Apparently modern rotors are made so thin that they can't be cut to remove a warp. If they were cut there wouldn't be enough material left and they would warp even more when heated up.

I was really surprised - and kind of PO'd at Nissan for using thin rotors. I hate the vibration, but not $500 worth. BTW, the shop advised against the brake job since there's no safety issue and plenty of brake pad left.

zoemayne

iTrader: (4)

If they need to be changed you can avoid the dealer markup by ordering them online. There are good quality non oem rotors out there.... and the oem usually always cost less... I find it hard to believe all 4 of them need to be replaced when there is little vibration and miles. Maybe only the two fronts would make sense.

ChrisMan287

iTrader: (34)

It's probably the front rotors that are warped. For what it costs for new aftermarket ones, I wouldn't even bother with having them cut.

Get some aftermarkets and do them yourself. It really isn't that hard.

BBmaxi

iTrader: (1)

this rotor thing among repair shops and dealer service is a whole big scam.

I know this from constantly changing my wheels every few months and not having any rotor problems (unbolting and rebolting on the wheels)

so here's the deal. Mechanic shops and dealers always suggest u turn the rotors when u change your pads EVEN WHEN THERE ARE NO VIBRATION ISSUES. Their explanation behind it is that "to match up the new smooth surface of the new brake pads".....It never made sense to me either but most of us just went along with it right ?

but the problem with them doing this is that it wears down the rotor surface area A LOT every single time u turn the rotors. "turning" simply means shaving down the surface area of the rotors so that it's smooth. That first turn causes the rotor to lose a substantial amount of thickness which WEAKENS the steel. That first turn is when the rotors are sure to WARP making it useless after few thousand miles of usage since u can only shave down the surface area so much.

so don't turn the rotors. U should never ever need to.

My rotors have never been turned and I get absolutely zero vibration issues. I've taken off and on wheels at least 20 times so if there's anyone who should have rotor problems, it should be me.

when it's time to replace the brake pads, just replace them. DO NOT turn the rotors.

boatguy272

Worst advice ever !

BBmaxi

iTrader: (1)

so what's your advice ?

RCM78

You don't have to turn the rotors when wheels are changed.

If new pads are installed it's best to have the rotors resurfaced. this usually takes .010" of metal off both sides of the rotor and will ensure that your new pad surface completely mates with the surface of the rotor.

If you don't replace the rotors or resurface them when installing new pads then only small portions of the new pads will grip the rotors severely diminishing braking capacity. It will also wear out your new pads much faster.

Whats more important, Braking performance, or saving a few bucks?

Like the OP said. Most rotors made nowadays can't be resurfaced. Especially rotors made in china. The metal sucks!!!

Braking Performance dot com makes a quality product that can be resurfaced. I also like Brembo OEM replacement rotors.

Racerbox77

Good advise.

BBmaxi

iTrader: (1)

did u even read my posting ? I NEVER said u need to resurface the rotors when changing wheels.

my whole point for me referring to changing up my wheels often is because mounting wheels frequently tend to warp the rotors if the bolts are not torqued correctly or torqued too tight.

BBmaxi

iTrader: (1)

ok so let's break down your logic one by one.

so according to your statement, the rotor should be resurfaced or replaced to match the "NEW" smooth surface of the new pads right ? otherwise you will never have full contact to the "NEW" brake pads.

If your statement is factual, this means the brake pads are NON MALLEABLE and should NEVER WEAR OUT... and that the brake pads itself is a harder element than the rotors itself.

BBmaxi

iTrader: (1)

but aside from all the debate, if nissan is using such junky materials for their rotors then I'll never buy a nissan again.

having to change the rotors every single time u change your pads is pretty ridiculous. That's a 700 dollar cost every 40k miles. no thanks.

Maximam

Everyone has a different opinion here but here is mine.

I do not turn my rotors with a pad change, period. I also do not turn my rotors when they get warped, I replace them.

My opinion was formed on many raceways in California, Nevada and Arizona doing battle with both the SCCA and NASA. :-)

dfj240

iTrader: (1)

Whether or not one should change, turn, or leave rotors should be on a case by case basis. I have had a good bit of experience mixing all three methods involved. It is typically good practice to at least turn them, just the same as it is good practice to resurface the flywheel when changing a clutch. A smooth surface for the material to mate to makes a difference in pad wear and pad performance.

Is it absolutely paramount that they be changed or turned every time new pads are installed? No. But if the rotors are warped then it's time for new rotors. Plain and simple.

If the rotors have a good smooth surface as they are then there really isn't much good to be had in turning them as they will not have any real effect either way.

The pads are indeed malleable, but if the rotor surface is not smooth then the pads will not be able to apply the same amount of pressure as they would if the surface was smooth. Does that mean your pads are going to deteriorate in 2,000 miles? No. But there will be a bit of difference in how long the pads last and how they wear, which, in turn, can possibly cause grooves to begin forming on the rotors.

In the end though, it's a judgment call based on someone who has the experience to tell whether any servicing of the rotors is required or otherwise necessary.

dmcmahan12

I will just leave this here. http://www.tirerack.com/brakes/tech/....jsp?techid=85
Continue.

boatguy272

ALWAYS at least turn rotors during a pad change,,,,,,even if only to break the glaze on the rotors........ OEM rotors are so thin these days and aftermarkets so cheap,,,, I don't even bother trying to cut them,,,, just replace,,,,, not to mention the time saved on brake jobs

Matt93SE

iTrader: (44)

Sooo much misinformation here guys...
1. That shop is most likely stupid. Specs from the FSM:
Standard thickness (new) 28.0 (1.102)
Minimum thickness 26.0 (1.024)

1a. In 34k miles, I doubt your rotors have been worn down enough to put them under minimum thickness.

1b. The wear surfaces of modern day rotors are about 1/4" thick each side. These specs limiting to 0.08" of wear is asinine. Yeah, the parts store won't want to turn them below that, but it's not going to cause your car to immediately assplode when you put them back on. I've trimmed 1/4" off some really bad rotors once and put the back on the car. (didn't have a choice since they were a custom Skyline brake kit and you can't just go to Autozone and pick up rotors for an R32...)

2. "warped" rotors usually aren't physcially warped. They are coated with uneven pad deposits because the OEM pads are junk and not made for anyone but Grandma driving your car. After just a couple hard stops, the pad material will deposit on the rotors unevenly and cause grabbing where the friction level changes on the rotor.

2a. The fix for that is quality brake pads that can stand a little more heat than a 3 block trip to the grocery store. I've run Hawk HPS on my street cars for the last 15 years and have never had a problem with them. My wife's DD uses whatever the 'premium parts store' brand was in stock- Wagner or Raybestos or Bendix. They're about $50 a set. I've used all of them on street cars with good results and none of this warping bull**** people complain about.

3. When simply installing new brake pads of the same type/compound, there is absolutely no need to turn the rotors. the materials are the same, and the pads will quickly seat and mate to the rotor surface conforming to any irregularities in the surface. It'll do this in the first 20 miles of driving, even if you don't attempt to bed the pads in.

3a. When you turn/resurface the rotors, they leave a VERY rough surface for the pads to grab onto and this wears the pads much more until the surface is worn smooth through braking action and wear. you use more pad like this in the first 5 miles than you will in the next 500 miles on the road. The only time you should ever have to resurface your rotors is when you've let the pads wear down metal to metal and you've put grooves in the rotor surface. Then again,

4. to repair "warped" rotors that have zero mechanical runout, the easiest fix is to simply sand the surface of the rotor with fine sandpaper (yes, by hand) or a sanding disc to remove the glaze on the surface, and then install your new pads. The different type of pad material will quickly redeposit on the surface of the rotors and you can move on with life.

5. I have noticed that Nissan uses a very soft iron in their rotors, which tends to have more problems than most aftermarket rotors. I don't know why, but that's just how it is. Pick up some Brembo, Centric, StopTech, or DBA rotors and they will do much better than the OEM soft grey iron.

gizzsdad

This^^^^^^^^^^^

assiduous

what mat93SE said. I especially agree with #3. I always found that cut for new pads unnecessary. Like it is even possible for the pads not to seat in the rotors. You put two surfaces grinding against each other on high speed and hope they won't seat.
I never bother with warped/vibrating rotors. They usually have some miles on them already, and cutting them will reduce the leftover life anyway. Never tried sanding by hand but I will. Perhaps on my older cars.
However I have had a lot of bad experience with cheap rotors. Even brand new they are garbage. There is nothing good in autozone or advance auto parts. The things will go vibrating after only a thousand miles. Then I got angry and bought these cryogenic steel rotors from tirerack
http://www.tirerack.com/brakes/brake...2&autoModClar=
I has been the smoothest brake pedal I have ever had for 4 years now on my Subaru. Definitely not gona skimp on rotors for my maxima when the time comes.

Racerbox77

Good, correct information here.

BBmaxi

iTrader: (1)

so far looks like half says to resurface and the other half says not to.

I say use some common sense and cut em or replace them every single time. The goal here is to spend as much money as possible when doing your brake service.

Matt93SE

iTrader: (44)

.. And be sure to have only ASE certified master mechanics work on your car. Because nobody else knows more about fixing **** than a guy who read a book and took a test for a patch on his sleeve!

RCM78

I perform my own brake service on my cars and motorcycles. On cars it's cheep enough to replace the rotors and pads.

On bikes since I have full floating rotors I just scuff the surface with scotch bright and bed the new pads in.

I have to admit the oem rotors Nissan uses are complete junk. I bought my maxima with 32,000 miles on it and the rotors were shot. Dealer replaced rotors and pads, now less then 20,000 miles later I'm getting a pulse in the pedal.

silberma

You are out of options, virtually all car makers use rotors with very little margin for resurfacing.

MaximaDrvr

iTrader: (1)

I don't know what you guys are doing to your cars. I have an 09 with 102,000 miles, and I'm still on the original front pads and rotors. I'll replace them near the end of this year.
I only developed a slight vibration within the last month, so over 100,000 miles on the car.
The rear brakes lasted 60k the first time, and I'll do them again when I do the fronts.


You can warp rotors. In my many years as a mechanic, and even more years driving, I have not seen it from over-tightened lug nuts. You can do it by driving hard and then going through a puddle and cooling off the rotors rapidly. There are some instances where turning a rotor will help, but if you are paying the to have them taken off, just have them replaced. If you are doing it yourself, don't waste the time to take them somewhere. Just order some quality replacements.

KGMtech

FWIW, all the OEM's (well maybe except Ferrari, Porche, Lambo, etc) are using the thinnest possible rotors for their disk brakes. It reduces unsprung weight, and reduces the rotational mass of the wheels = better fuel economy.

The risk of these thinner rotors is if the wheel lug nuts are tightened incorrectly (insert standard garage monkey / gorrilla statement) these thin hunks of cast iron will warp.

What I have noticed in the last 10 years is that the aftermarket prices for rotors has become much cheaper with the introduction of more Mexican and Chinese parts. And, if you buy name brand - it really doesn't matter where it's produced..the quality will be just fine.

assiduous

You are 100% correct on the effect of heavier rotors, but I doubt that's nissan's motive. I bet its because thinner = cheaper. The weight savings on a rotor are absolutely invisible compared to the weight savings on the wheels - first, wheels are much heavier, and second, wheels have much larger diameter, and it takes exponentially more energy to get the wheels rotating or stop them. And yet Nissan goes with a crazy 57lb wheel (rim+tire) on the reg, and who knows how much the 19s weight. My 97 Maxima has 15" rims and the whole rim+tire weighed 31 pounds. If rotational weight was a concern that thing would weigh 40 pounds, which is what I have right now.
But they try to appeal to the .. i don't know how to call those people who go gaga for the big wheels.. I think 17" wheels are pretty big already. Just make smaller wheel wells so they fit snug, like BMWs always do, even with 16s. Its all proportions and illusion. I admit I don't like the big gap between my tire and the fender, but I sure as hell arnt puttin any bigger wheels. Anyway, digressed severely, my point was, im pretty sure their only concern was cost.

BBmaxi

iTrader: (1)

maybe nissan changed the manufacturer of their rotors from 2010 to 2014 maxima because my 2009 is not having any issues with the rotors.

it would **** me off if the quality of the rotors have gone down to disposable status.

there's a reason why nissan has such horrible resale value, this is one of the reasons.

from now on I only buy toyota seriously speaking.

Maximam

YUP! Best car I have owned right here:

silberma

Maxima's have a low resale vale because there is not as much demand for them as Toyota's and Honda's. If you keep your new car for a short duration resale value is an important point to consider. On the other hand, if you buy used or keep your car for many years it does not matter.