Brake rotors keep warping

[Virtus_Probi]

Originally Posted By: Trav
+1 One of the most important steps. Cleaning the hub face, the back of the wheels and center hole so the wheel slides on easily is very important especially with aluminum wheels. A tight center can cause uneven tightening.
You can use a drill mounted wire wheel or what I finds works well on the flat wheel surface is a 5-6" round random orbit sander with 120-150 grit paper, it does a nice job,
just sit it on the back of the wheel nice and flat and run it, move it around slightly but do not move it off the center too much, you want it uniform.
Don't worry about pits you just want the junk off.


I never thought about what's in bold...thanks for the info and I will do this next time I swap my wheels.

 

[Kira]

Gotta chime in due to the large quantity of crud I removed from my hub face and wheel mating surfaces.
I did so only a few months after the vehicle had 4 tires installed so you know the dealer didn't bother cleaning them.
To keep corrosion down I carefully sprayed the surfaces with 5-56, a hearty moisture repellant.

 

[Rolla07]

Im going to go against the grain and suggest this: dont do anything. Keep driving with it a few months and see if it improves. Pretty sure its deposits. I had same issue and eventually no more pulsating. Maybe do some hard braking as if to break in new pads?

 

[Trav]

Wheel pulsation also transmits increased movement on the tie rods and other steering components and the steering rack/box, no benefit in letting it go only negatives.

 

[ram_man]

I did measure them when I put them on I don't remember what they were but I remember they were in spec I even matched low spot to high spot on the hub just to be that much more thourough. I scrubbed the hub area with a scotchbrite pad and everything. I did it very by the book which isn't usually ever done but I did it to take out any element of error.
Back brakes do appear to be working correctly as well

 

[Trav]

Did you make sure the caliper is sliding properly and the pads have free movement? It may just be garbage parts as others have posted, coming from AA it wouldn't be a big surprise. Get some decent stuff from NAPA.

 

[JLawrence08648]

I'd first check to see if the rest brakes are working as they are suppose to be. If they are not then the front brakes will be working harder, thus overheating then warping.

Could the front brake slides be sticking and not releasing the pads?

Possibly the calipers are not releasing the pads against the rotors?

 

[quint]

I have pretty much always used the cheapest Autozone pads and rotors on my 240sx, and for the longest time, it was a major shaker if I even looked at the brake pedal. New or machined rotors usually cleared it up for a few weeks, then it always came back. Finally got tired of it and after removing the rotors and then cleaning the hubs as described above, getting the junk off the hub area of both sides of the rotor, cleaning the wheel mating surface and using a very light smear of high-temp brake grease between the wheel and rotor, I'd say 80% of the vibration was immediately gone.

A few months later the lifetime warranty semi-metallic pads were worn and since they didnt have any in stock, they gave me their house ceramics as replacement. Did a pad slap and about two weeks later whatever little vibration there was disappeared forever and hasnt come back since. Thats been about two years. Rotated the tires last week and everything still looks great.

Did the same thing on my Sequoia (just cleaning the hubs, rotors and wheel mating surfaces) and while the improvement wasnt as dramatic as it was on the 240sx, it did remove a very significant amount of the vibration during braking, and there was absolutely plenty beforehand.

So yea you could say I'm a big fan of cleaning up the junk off hubs. I've done several family/friends brakes since I started doing this and every one of them as had a decent about of crud to clean. I'd give that a shot before I replaced anything or did anything else.

 

[The Critic]

Originally Posted By: Trav
+1 One of the most important steps. Cleaning the hub face, the back of the wheels and center hole so the wheel slides on easily is very important especially with aluminum wheels. A tight center can cause uneven tightening.
You can use a drill mounted wire wheel or what I finds works well on the flat wheel surface is a 5-6" round random orbit sander with 120-150 grit paper, it does a nice job,
just sit it on the back of the wheel nice and flat and run it, move it around slightly but do not move it off the center too much, you want it uniform.
Don't worry about pits you just want the junk off.

Agreed. You want the hub flange looking like this:

 

[mightymousetech]

Could also be a bent hub. Give it a quick measure while the rotor is off.

If the rotors keep warping, there has to be something else going on, it is not the rotors fault.

 

[wallyuwl]

Originally Posted By: Garak
How about checking runout upon install, as cos alluded to?


Yeah, very well could be runout. This was the issue on our 2003 Vibe that kept pulsating new rotors.

 

[Trav]

A bent hub will cause shake at all speeds with or without brake application.

 

[Trav]

Originally Posted By: The Critic
Originally Posted By: Trav
+1 One of the most important steps. Cleaning the hub face, the back of the wheels and center hole so the wheel slides on easily is very important especially with aluminum wheels. A tight center can cause uneven tightening.
You can use a drill mounted wire wheel or what I finds works well on the flat wheel surface is a 5-6" round random orbit sander with 120-150 grit paper, it does a nice job,
just sit it on the back of the wheel nice and flat and run it, move it around slightly but do not move it off the center too much, you want it uniform.
Don't worry about pits you just want the junk off.

Agreed. You want the hub flange looking like this:




Yep it should 100%. You use the 3M (or similar) tool too I see.

 

[nthach]

Originally Posted By: Reddy45
Betcha this'll fix it.

https://www.zeckhausen.com/catalog/index.php?cPath=6446_6443

Don't follow that procedure with ceramic/organic pads on a typical car, or you will have pad deposit issues or damage the compounds. That procedure was meant for semi-met or "track" pads.

Try cleaning up the hub and wheel surfaces of any rust and maybe having a machine shop give the rotors a light skim on the lathe or sanding the rotors with 80 grit paper to get rid of any pad film. Then bed in the pads with this procedure instead:
http://www.wagnerbrake.com/technical/technical-tips/break-in.html

 

[nthach]

Originally Posted By: Trav


Yep it should 100%. You use the 3M (or similar) tool too I see.


I've been using a wire brush and a cup wheel for a while just to knock down the rust but I can't seem to get between the wheel studs and hub lip. I need to get this for the next brake job I do.

 

[Trav]

https://www.amazon.com/3M-07547-Scotch-Brite-Roloc-Cleaning/dp/B0013HHNPY

 

[The Critic]

Originally Posted By: nthach
Originally Posted By: Trav


Yep it should 100%. You use the 3M (or similar) tool too I see.


I've been using a wire brush and a cup wheel for a while just to knock down the rust but I can't seem to get between the wheel studs and hub lip. I need to get this for the next brake job I do.


3M tool by itself will leave you with this:



As you can see, there is still rust between the studs and the center of the hub flange.

To remove the remaining rust, I attach a wire wheel like this one to my drill, and then hold it perpendicular to the hub flange to try to remove the remaining rust:

 

[Trav]

Same here. Once its clean I put a very thin film of never seize on the flange, put the lug nuts on then check the runout. While not mandatory its not a bad idea to check the caliper bracket alignment especially with reman stuff.

 

[hemitom]

Originally Posted By: AITG
I have a 2011 F150 and I have had problems with pulsation (frequently mis-diagnosed as "warping") through two rotor replacements. About two years ago I had new pads and rotors installed front and rear. This time I tried seating in the pads. I made six hard stops from 35 down to 5 mph as rapidly as I could, followed by six more from 50 to 5 mph. I then drove the truck for 15 minutes without hard braking to allow the pads to cool.
So far, absolutely no pulsation. The theory is that this lets the binder in the pads stabilize so that pad material won't transfer to the rotors.

I always do this!! never had an issue even with el cheapo rotors and pads.

 

[Trav]

Lot of guys have ended up with bad squealers though doing this. For street cars I prefer to just apply the brake a few times while giving gas at about 30 mph. 3-4 times is enough then drive it normally. The bonding agent does not need to be cured on street brakes unless specified by the manufacturer.
Racing or hi po brakes are another story, always follow the pad manufacturers (as opposed to generic instructions) recommendation, the bonding agent may need additional curing for full effect.