Turning my own rotors

Overheal

Aloha strangers. Neighbors. Friends?

I have a 2006 Jeep Grand Cherokee Laredo (2WD 3.7L). The rear brakes (and rotors, I believe, were replaced 15 months ago. Brake fluid flush was also done.

Anywho, I've had a lot of irregular braking; in terms of braking drag, as I slow down my car feels like "

---

_---_---_--_----_---_-__-_--_-___

---

_

---

_" etc. so I figured a rotor problem, and probably a front rotor problem. I've owned the vehicle since 2009 and I doubt the previous owner ever changed anything on it.

Get it to a dealership, the service center said my brake fluid looked awful while out of town. Indisposed to dispute that, since it just got done recently (relative to my inanimate car), I let them go for it. That, and 15 months ago I moved upstate - so imagine moving from the flats to the mountains. I've been a lot harder on those brakes I'm sure. 6mm on front and 8mm on rear pads if you were wondering. The front pads may be the originals, I couldn't tell you, except I've never replaced them and I got the car at 38k and its 94k now.

Get the jeep back and the problem still exists. After the diagnostic the mechanics admit they checked the pads but not the rotors - my rant for this particular service department may be spared for another forum. The service manager admits that while they would charge me $90 to turn the rotors themselves, it's something you could do yourself with the right equipment.

Through the local university I have access to CNC lathes. The mgr. suggested no more than '2 turns, about 0.03 inches'.

My question about this is, would it be simpler to replace the rotors? is it worth the trouble of installing myself? As far as replacing goes I was either looking at these Duralast Iron Alloy (http://www.autozone.com/brakes-and-traction-control/brake-rotor-front/duralast-brake-rotor-front/jeep/grand-cherokee-2wd/2006/6-cylinders-k-3-7l-sfi-sohc/951700_172993_2708/) or their Carbon Steel (http://www.autozone.com/brakes-and-traction-control/brake-rotor-front/duralast-gold-brake-rotor-front/jeep/grand-cherokee-2wd/2006/6-cylinders-k-3-7l-sfi-sohc/466942_172993_2708/) or any other suggestions forum regulars may have. My risks are that I strand my car at the university if I did something royally stupid (chance: very low - either it fixes the problem or I'm stuck with the problem, I'll hardly destroy the rotor using a lathe properly), or just excess hours and time trying to uninstall and reinstall rotors rather than have a professional do it.

Any tips? Worth the hassle? Other things I should diagnose? Because I'm not 110% sure that it is in fact the rotors - but I'm fairly darn sure, through logic and stuff.

cletus

I'd I'm reading your post correctly, rear discs have been changed, but not front. If the local college have a cnc lathe they probably have a micrometer. I'd check to see how close they are to minimum thickness, you'll know pretty quickly whether they can be put on the lathe.

Personally, I would be inclined to just change them rather than try turning them, as you really want the stop to work on your car

The actual changing of the discs is not that big a deal, you could probably have a shoe at it yourself, save the labour costs

mullingar

Yes, one of your discs is warped.

To determine which axle, is the vibration also felt through the steering wheel when braking? Yes = front discs, no = rear discs.

Get you hands on a run-out gauge. Take one front wheel off and re-attach the wheel nuts. Place the run-out gauge on the shiny side of the disc and slowly turn the disc and see what the run-out is like for high/low spots. Repeat the other side. Anything north of 0.1mm might be felt.

A word of warning. All discs have a limited life and manufacturers specify the minimum thickness of a disc. Do not be tempted to lathe below that thickness.