Minimum rotor thickness and pad thickness before replacement?

[ALEV8]

I'm experiencing shuddering while braking highway speeds. Just started about in June. So I bought some new front rotors. When I went to install the rotors I noticed that the current ones looked brand-new, and when I measured them with a caliper they are the same thickness almost as the brand-new rotors which have arrived from centric. Maybe it's the pads, or should I just do both and shut up?

I just can figure out why after two years I have shudder and the **** rotors are so close to new....

At a loss here.

[clarksongli]

check flatness and runout of the current rotors with a magnetic base and a dial indicator.

Stick the base to the spindle and set the gauge on the face of the rotor....spin the axles and see if they are relatively flat....pulsation comes from warping and transfer layer build up.

[mcbit500]

I'm experiencing shuddering while braking highway speeds. Just started about in June. So I bought some new front rotors. When I went to install the rotors I noticed that the current ones looked brand-new, and when I measured them with a caliper they are the same thickness almost as the brand-new rotors which have arrived from centric. Maybe it's the pads, or should I just do both and shut up?

I just can figure out why after two years I have shudder and the **** rotors are so close to new....

At a loss here.

You may also get shudder if there is play in any of the front suspension joints.

[ALEV8]

Wheels off today checked both visually and there's barely any wear on rotor or pads. I cannot measure runout as I don't have a gauge. This shuddering came on very suddenly this summer. Makes me think it is the front lower control arms...likely will need a pro to look rather than start replacing parts wildly nilly...

[clarksongli]

If you feel up to it, you can unbolt the lower control arms and swing the arm out to look at the bushings...this is a typical play zone.....just try not to touch the outer spindle ball joint bolts, or you may need to get another alignment.

Basically:

1. Disable air suspension

2. Jack up front of car

3. Take tire off

4. Unbolt the front and rear lower control arm bolts.

5. let the entire assembly swing out....and take a look at the bushings for cracks/breaks