Brake rotor minimum thickness?

[OR VietVet]

I am aware of all the things pointed out in the links and the term "warped" is just easier to say than lateral runout and all the other terms used in the articles. The hub surface, the proper lug nut torque, swapping a rotor to an old hub, bearings play.....I get it.

I will continue to always get new rotors and when asked I will recommend the same. What I should have also said in my recommendation is that all the other things mentioned in the links should be inspected and addressed too.

I know I have said it many times here, that the "brake system is the most important system" on the vehicle. If I am getting new pads, I am getting new rotors. I will also never install new pads without new rotors on anything I work on here at my house. Good luck.

 

[OR VietVet]

I will say this as well, I forgot to say that we had a runout gauge that would clamp to the spindle or a spot where the caliper mounted. We would check the rotor runout, before and after.

 

[OR VietVet]

The older I get, the less I want to type for 15 minutes to get everything in my head, down in a post.

 

[Fless]

The older I get, the less I want to type for 15 minutes to get everything in my head, down in a post.

I resemble that.

 

[swathdiver]

My youngest had been kicking the can down the road to do her brakes, still original after 80K plus miles. Fronts have plenty of meat left, rears were worn to the wear sensors the other day so she decided Saturday would be the day. Only, she didn't get started until 1 pm and had some kids come over to do the work without asking me.

I took charge at that late hour, sent the help home and sent her inside to make dinner and started rummaging around for the parts that her sister put away for me, somewhere really good, cause we couldn't find them! The parking brake shoes would not let the drum in hat rotors off without a fight, the puller I used last time, 5 years ago, was nowhere to be found. Rain clouds were forming now and my helper and I were getting hungry! After cleaning up the mounting brackets and slide pins with new grease, the clouds let loose the rain on top of us. Done for the day.

Sunday after church we got back at it and did a pad slap. The original rotors had no grooves in them, the pads wore evenly, there's no vibration when stopping. We bedded the pads, rotated the tires, torqued them to 140, set the air pressure, tire positions and recorded the tread depth for all. Back on the road.

While I did not like putting a $150 set of pads on without the new Akebono OE rotors, circumstances forced us to get it back together quick.

The truck has been pulling a 7K pound dump trailer this week and stops just fine, even when my little one didn't have the gain set high enough. I fixed it for her tonight when she brought the Big Tex trailer home.

I'll schedule the next availability and change the fronts out properly along with the brake fluid. There was a time when turning the rotors was the thing to do and can still be done. I was going to save these for my other daughter's truck, she could have had them turned for free at work but it was not to be with this set.

Anyhow, 88K miles on the rear brakes is pretty good for a GMC Sierra I reckon. I got 121K out of my first set of rears and have 64K on them now. Still stops from 60 mph in under 145 feet.

Don't know what aftermarket rotors weigh, my fronts are about 27 pounds and the rears are almost 22 pounds each.

 

[houstontaylor]

After I quit having old rotors machined and just replaced them I have never had break pulsing again. I think the lathes are not accurate enough to get the rotor surface exactly perpendicular to the axis of rotation. And in that case pulsing of the brakes is inevitable.

 

[Fless]

After I quit having old rotors machined and just replaced them I have never had break pulsing again. I think the lathes are not accurate enough to get the rotor surface exactly perpendicular to the axis of rotation. And in that case pulsing of the brakes is inevitable.

I don't think that's the lathe's fault; the rotor hub may not have been cleaned properly to mount correctly on the lathe. I've had lots of rotors turned, without any issue of them being cut improperly. I clean the hubs thoroughly before taking them in.

 

[OR VietVet]

In my shops, the hubs of rotors were cleaned thoroughly and races were checked to be sure they were seated properly, before mounted on the brake lathe. The hubless rotors were buzzed to make sure the mounting surfaces were clean and flat and all surfaces were checked on the machine for runout and if it was enough so that the finish product would not be in minimum thickness specs, we stopped and did not machine. Let them take to a parts store that will machine ANYTHING.