The GM spec for runout is 0.002 or 0.050mm. The closer you get to 0, the better the result. The lighter the vehicle the more you notice the runout being out of spec.

Since you are getting some pretty poor results with your rotors, you need to look at all of the possible problem areas. I was kidding, but half serious about how you drive and you noted that you said you drive pretty normal. SWHouston asked if you drive with your foot resting on the brake and you don't. Rotors warp due to excessive heat, through spirited driving, weather conditions or load, such as pulling and stopping heavy loads.

I understand that you don't want to get into the brake lines. I hear you, it is a big job, especially if you get into the steel lines. However, it may be part of your problem.

When your truck is new the inside of the flex lines are to spec. When you press the brake pedal, the full pressure of your brake application makes it to the calipers and you get full braking force. Then when you take your foot off the brake, the fluid returns back to the master cylinder. As the lines age, the rubber starts to swell. This swelling hampers the action of the brakes for both application and release. Often, if the swelling is bad enough, it will not allow a full release of the caliper and holds the caliper partially applied.

You should also try and service the brake slides a couple of times a year to make sure that the slides are smooth. This will also help to reduce drag. I find that using a high temperature brake lube is extremely important or you risk the lube melting and not lasting.

 

Over torquing or uneven torquing on the lug nuts will also cause rotor warping. Crappy rotors will also warp.

Tapered shims are available if you don't want to turn or replace the rotors.

 

The wheel nut torque spec BTW is 140 foot pounds....
Torque wrenches are relativity inexpensive at Harbor Freight and should be accurate enough for wheel nuts...

 

Quote:

Originally Posted by Rickoo

lol....no problem. But no, I'm not one that rides the brake. One foot driver for me.

Good, glad you're being a good Sport about that, I had to ask.

I see some very good information being given here !

 

When they warped the last time (when the dealer did the job) I wondered if they didn't torque the lugs properly causing the warping.

I have and use torque wrenches in everything I do. Have some calibrated Matco wrenches I have 100% confidence in.

They were torqued to 140 fl lbs. at last replacement.