Warped a rotor! What sort of bad boy behavior was involved? ;>))

I haven't done the brakes as yet but I am changing pads and touching up my wheels, soon hopefully. So I'm looking forward to that video.

Bob S.

 

Warped an STR rotor!! They're not thin and crappy y'know!!

hmm, stopped with brakes applied (pads in contact) with very hot rotor?

 

I believe its a rear that is warped. It may have been warped when I bought it. I dont have any highways near me so the highest speed limit near me is 55mph. Well took a trip for a family reunion and on some back roads was getting some pretty bad pedal pulse from slowing down at high speeds. Doesnt pulse when driving slow and braking only when slowing from about 60+. So I think its my rears. I also still have some noise when driving really slow that I thought was the 2 piece lugs, well I no longer have the 2 piece lugs so I think its the rotors contacting the parking brake pads cause I'm getting a weird wear line on the rears. I picked up the crossed drilled and slotted black ones from brakeperformance.com so I'll give them a try and since the rotors dont seem heavily warped I'm gonna turn which ever set I find warped and have them on hand as spares.

 

Sometimes it pad material deposition and not actual warpage. If you're using cross drilled rotors that might be an issue as well. Pad material can accumulate in some of the holes, build up and cause pedal pulsation. That's why I never put them on my cars. I've see too many issues with that. It might not be that in your case but it's worth a check. You can usually clear the holes with a drill bit or knitting needles.

Bob S.

 

I'm upgrading to the drilled/slotted rotors. The ones that I believe are warped are solids. I just figured I'd get new ones now and have the back ups as I will soon be unemployed so trying to get anything little that could become big fixed now while I still have an income. I'll be having them checked for warpage and if they are good and its something else I'll just keep the solids as spares.

 

Oh OK. Well if there's still time skip the drilled part.
You can get pad material deposition on smooth rotors as well.

Bob S.

 

There are several issues with brake pulsation
1 warped hubs
2 warped rotors
3 rust on rotors not where pads sat
explanation,,you always need to measure runout and parallelism of rotors with a dial indicator if you suspect warpage. .002 or less is spec with lug nuts torqued to spec after wheel is removed.
If its over .002" remove the rotor and check hub same spec.
Replace anything thats over .002"
parallelism is checking thickness variations of the rotor. This many times is the result of a car sitting and the rotors rusting where the pads do not sit. Then when you drive the car and brake the rotors are cleaned of rust which as we all know is the oxidation of metal. When the rust is cleaned, that metal is gone. Problem is that now the spots where the pads sat was not rusted and those spots are now high spots and create pulsations too..

 

Thanks for the info BRUTAL. I needed a reason to pick up a dial indicator and you just gave me one. I'll check them once my new rotors come in and I tackle this job. If its 3 and I have enough rotor left for turning I'll have them turned true and they will be my back up rotors.

 

moved your posts over here guys, it was muddying up the headlight fix thread...tsk tsk

 

But I like mud, hense the 4x4 truck
actually I hate mud or the cleanup of it.
Just make sure you check the runout of the hub if the rotors are out of spec. I just did a car last month that another shop replaced the Brembo pads and rotors for brake shimmy and the problem was still there lots of $$$ later. Needless to say the owner wasnt happy when I told him he only need a hub and not the new pads, and rotors. The hubs should really be "0" in my opinion cause ANY out of spec is multiplied out to the end of the rotors. IN his case the hub was .002. the new rotors were .007. After I put a new hub in, the same rotors were then at .001"

 

But what the heck causes a hub to go out of spec like that?
I've had them with gunk/rust/build-up on them.

Bob S.

 

Potholes, kerbs, etc?

 

I would think that it would have to be a major event that also destroyed a wheel or suspension pieces as well. So you know that something major had happened.

Bob S.

 

This weekend when I get my rotors I'm gonna make a side video showing how to measure runout. That way if you think you may be having a problem you can check before buying new rotors. I hope mines good I'd really hate to have a bent hub. BRUTAL if my hubs out of spec does that effect the halfshafts in the rear at all?? Also would the bearings be shot also or would I be good with just a new hub??

 

It depends on why it bent, potholes, lightly damaged bearing if hub is bent. On a stype they come as an assembly. Im working on a 03xk right now that has 2 bent hub .005, and .007 the rotors are .009 and .015. 2 new hub and bearing and ill recheck when done, but past experiance has shown that the rotors are normally ok if the hub is warped. Once the hub is fine then the rotors run true(normally)

 

Well even if my rotors are fine I'm still installing these bad boys that the brown truck just brought me today. Hopefully I'll only have 1 bent hub if any as I'm seeing they arent cheap.
Thats a standard 8.5x11 sheet of paper couldnt find my ruler.