"Warped Rotors" fixed themselves...

[Capnemo]

My recently acquired '97 Limited had quite the shake on braking, had read all the theories of warped discs vs uneven brake deposits. Obtained everything I need for the TBU, but took a long 2k mile road trip first. By the time I got home, the shudder is gone and my braking is smooth. So while I do believe T4R discs can be warped, mine I believe had uneven deposits which over the high speed freeway braking etc and long trip, were evened out and rebedded themselves.

Still going to be glad for the TBU...

 

[audiness]

i read somewhere that warped rotors is actually a myth, and that its just uneven brake pad deposits on the rotor.

 

[rightyouareken]

i read somewhere that warped rotors is actually a myth, and that its just uneven brake pad deposits on the rotor.

This. Sometimes what people assume are warped rotors are just rotors with uneven pad material deposits on them. They can often be fixed by using a wire brush attachment on a drill or grinder. Sounds like maybe what your problem was. If I had to guess, I'd say your long road trip allowed the brake pads (which ride against the rotors lightly all of the time) to scrape off some light deposits during your drive...lightly "resurfacing" your rotors for free as you drove. Either that, or they just distributed the deposits more evenly.

Also, you can experience brake shudder when you have a sticky caliper piston or bad tie rods/ball joints, though it sounds like you don't have this issue since yours went away.

 

[Jebb209]

Warped rotors are definitely real... I put mine on a brake lathe and could watch the cutting tool lightly "bounce" off the rotor face as it rotated. I resurfaced them and my braking was smooth as can be.

 

[gamefreakgc]

It is and it isn't. I've had both truly warped rotors as well as the wobble with brand new TBU rotors. The rotors can and will definitely warp if the driver is hard on them and overheats them on a regular basis, that's how I purchased mine. Putting a pad imprint on the rotors is also a possibility when you are tesing the speed governor at 100 MPH and then stupidly come to a complete stop. Braking, even lightly from from 100-0 creates a lot of heat, who knew?

Anyway, a re-bedding process took care of the pad imprint that was causing my wobble post-TBU like the OP experienced.

 

[TheDurk]

I have 20 years and 200k on my factory brakes. (pads and rotors changed, but not upgraded. Factory calipers.) I have never experienced brake shudder.

I attribute it to three things. 1) No real mountains around here, so serious overheating doesn't happen. 2) I always bed new rotors per manufacturer's instructions. 3) I always hand-torque lugs to 83 ft-lbs., and check it after anybody else pulls a wheel (very rare).

Not sure it makes any differnce, but if I think the brakes are hot, I won't hold the truck at a light or stop sign with the foot brakes. I'll use the e-brake, which engages only the drums.

 

[Jidaran]

Warped rotors are definitely real... I put mine on a brake lathe and could watch the cutting tool lightly "bounce" off the rotor face as it rotated. I resurfaced them and my braking was smooth as can be.

Wouldn't this also happen if they weren't physically warped but just had uneven deposits?

 

[rightyouareken]

Not sure it makes any differnce, but if I think the brakes are hot, I won't hold the truck at a light or stop sign with the foot brakes. I'll use the e-brake, which engages only the drums.

I think it absolutely makes a difference not to sit with brakes clamped on hot rotors. I live on a ~500ft tall plateau and have to drive down a fairly steep road to get on the highway. The road is 45mph and the hill has a stoplight almost immediately at the bottom, so I often arrive at a red light with my brakes hot. I've had brake pulsing issues with a majority of my cars over the past 10 years as a result. When I can remember, I consciously try to leave a bit of room to the car in front and slowly creep forward at the light so as not to "bake" my rotors with clamped brake pads all in one spot for very long if I can help it. But sometimes it's easy to forget, and I've generally had to get my rotors resurfaced every few years. My wife has had the same issue.

Also, I used to do track days in various sports cars and it was common practice not to put the emergency brake on when parking back in the paddock between run groups on cars that don't have separate e-brake pads/drums, or else it was really easy to get warped/badly deposited rotors.

 

[FunBobby]

i read somewhere that warped rotors is actually a myth, and that its just uneven brake pad deposits on the rotor.

StopTech released a technical paper debunking it a few years, unfortunately I can no longer find it. This article is pretty close to it: Clicky