My 2010 4Runner has 200,000 kilometers on it, and it's still running with the original rotors. Lately, I’ve noticed some vibration when braking at speeds over 90 km/h, so I decided to take a closer look. After removing the rotors, they appear to be in decent shape aside from some rust on the inner layer. The thickness is still good with only minor wear, enough that they could probably last a bit longer. However, I’ve already purchased new rotors, which I can’t return.

My question is, have I been driving too cautiously over the last 14 years? When do most people typically replace their rotors? I live in Alberta, where winter roads are tough with salt and ice. I'd love to hear from others about their experiences with rotor wear in similar conditions.

You need to have them tested for wear thickness and runout to fully diagnose. TBH at 120K they would be close to being done, so replacing them is probably the way to go. That said, do not count on the new ones curing the steering wheel pulse at 60 mph.

I’ve got the same decision to make. 140k miles on my original pads and discs and replacement parts on the shelf. My discs exceed minimum thickness by almost 3mm and runout is well within spec. My concern with replacing the discs is running into installation issues beyond my capabilities, like stuck or broken bolts.
…and I agree with Mr. slam regarding vibration.

Only minor wear, to me, screams that you should check and make sure all the brakes are working.

Had a 97 Saturn, and I replaced pretty much everything on the back except cylinders and lines when I got it, since the bearings were shot, and I found a screaming deal on the drums, pads, springs, etc. After a couple months of wondering why my braking was kinda weak, I pulled the drums off again, and everything still looked brand new. Turned out the cylinders, lines and banjo bolts were packed solid with rust, and I'd been on front brakes only the whole time.

I have about 270,000km on my 2012 and here's the replacement schedule I'ev had:

I did my fronts at 168,000km and about 260,000km

and rears at 65,000km, 134,000km, 195,000km and 260,000km

rears seem to go faster for some reason. good life you've gotten out of your rotors, but brakes and tires are places I don't cut costs. replace them since you have them and you will probably be fine for a while

You're definitely due to replace the rotors. However, your vibration could be because of a number of different issues, i.e. ball joints, control arm bushings or tie rods.

I typically DIY brakes and service on my audi and 4runner. The audi has about 95k miles on it and just within the past month started some pulsating at 60mph plus while braking. I changed the front rotors & pads yesterday and it wasnt a bad job. PBR Blaster and some banging of a mallet took the rotor off with little issue. Took about 40 minutes with 1st rotor I struggled with, and second one just came off. I spent about $270 in parts (front rotors, pads and rear pads) I had quotes from $1700-2200.

Having OEM brake rotors lasting into the 200k kms are normal ( '05 4R @ 200k , '00 AcuraRL @ 240k ). In your case the slight pulsations when brakes were applied at hiway speeds strongly indicated/suggested warpage in rotors ( most frequently with front rotors but my '00RL rear rotors caused pulsations when they were warped ). If you'er doing the work yourself, it'll not hurt to check for worn out tie rod ends and wheel bearings while you have the wheels jacked up and off the ground. Also if you have a dial indicator check for run outs of rotors and wheel hubs (w/rotors off ). A previous encounter with a curb can bend hub ( as it did for my '05 4R ). Believe factory specs for rotor run-outs is .000" - .002" max. If you'er confident your OEM rotors are still within thickness specs., have them machine/clean-up for reuse or spares. New non-OEM rotors ( and I've bought a few for my 3 vehicles ) are generally made from inferior material ( China ) and are crab shoots as to their longevity. I've never bought replacement rotors from any dealership so giving them the benefit of the doubt that theirs are of a better quality.

You had quotes of $1700 to $2200 for front rotors and pads? That is insane for a job that takes about an hour.

How do I check these parts to see if they cause the problem?

For tie rod joints, you can just use your hand to see if they are loose, i.e. try to move them back and forth. Or have someone turn the steering wheel from side to side while you look at the joint. If the tie rod moves without moving the wheel, the joint is loose.

Ball joints are a bit trickier to check out & takes two people. First jack up the car until the tire is just off the ground. While your co-worker watches the ball joint closely, use a long breaker bar under the tire to lift it. If the joint is bad, you will see a the top of the ball joint move more than the bottom (control arm) meaning it is loose in the socket.

fkheath's method of checking for worn joints at tie rod ends and ball joints are bang on with a second helper on hand. However if you are a onesie doing these checks, here's what I'd been doing. Jack up wheel, grab wheel @ 12 and 6 o'clock positions and see if there is play when you try rocking the wheel along this axis. If there is play, bad ball joint. Next, grab wheel @ 3 and 9 o'clock positions. If play detected when rocking wheel along this axis, bad tie rod ends. Note#1: when doing the tie rod check, first make sure steering wheel is lock in straight ahead position to immobilize steering shaft. Note#2: if there are plays when performing both these checks ,then you have a worn wheel bearing.