Pads or Rotors - Which is responsible for DTV?

[The Critic]

Originally Posted By: SubLGT
Originally Posted By: The Critic
...Without measuring runout and knowing the vehicle's maximum allowed runout, you're simply guessing what the problem is.


It seems most DIYers do not want to spend money on a dial indicator and magnetic base.


The HF dial indicator works fine and the kit is $30.

 

[greasegunn]

Originally Posted By: SubLGT
Originally Posted By: The Critic
...Without measuring runout and knowing the vehicle's maximum allowed runout, you're simply guessing what the problem is.


It seems most DIYers do not want to spend money on a dial indicator and magnetic base.


How many shops do you think actually measure runout?

 

[The Critic]

Originally Posted By: greasegunn
Originally Posted By: SubLGT
Originally Posted By: The Critic
...Without measuring runout and knowing the vehicle's maximum allowed runout, you're simply guessing what the problem is.


It seems most DIYers do not want to spend money on a dial indicator and magnetic base.


How many shops do you think actually measure runout?

Not many. I end up re-doing most "brake jobs" (that others have done) after 10-20k miles for pulsation.

 

[threeputtpar]

I think I can rule out runout because of the propensity of the problem to disappear when the roads are wet.

I've since installed a new set of Brembo FF rated pads and the problem persists when dry out. The pads that I removed were also FF rated, but at least I got the Brembos on closeout for $11. I'm really leaning towards replacing the rotors with a better set, I just don't want to spend the money replacing relatively new parts.

It's just an annoyance at this point and the vehicle stops fine. I really should be replacing the fluid as it's never been done and I can feel the pedal sponge during a hard application of the brakes.

 

[SteveSRT8]

Originally Posted By: The Critic
With white box rotors or resurfaced rotors, runout is usually out of spec at least 50% of the time. At least from what I have seen. Without measuring runout and knowing the vehicle's maximum allowed runout, you're simply guessing what the problem is.


Wow, I can get rotors that spec out fine more than 90% of the time in the GM fleet products. We have been known to machine brand new stuff for the SRT8, but any white box rotor would seem to be a [censored].

And I have never seen a driveway DIY guy use a dial indicator for anything. I'm sure there are a few exceptions...

 

[threeputtpar]

I've got about a week's worth of driving now on the replacement pads and they seem to have cleared up the issue. I was skeptical if they would do anything or not, but I'm now convinced that all FF rated pads are not created equal.

I thought everyone would appreciate the follow up on my results. Thanks.