Well Peter, I probably would have faired out better in the end if I tried to turn the rotor myself with sandpaper. I picked my set up today. They were ready at noon like the guy promised. Just by looking at the rotors when I got there, I could tell that they took off more than 8 or 10 thou on either side, so I asked them, and they said: "Yeah, we took off a bit more just to make sure they were straight, but you're still above spec." Alright... so I give them their $20 and off I go.

I get the rotors home, and immediately go out to the garage to mic them. One is at 0.808" (fair enough... still ok), but the other one is at 0.775" (WTF? Below spec?) OK, I'll put them on and give them a call tomorrow to see what they say.

I get the rotors on, put the dial indicator on to see how well they did getting the runout out of them. First one 0.028" and the second one 0.025"! Ten times the maximum spec of 0.0028"... Now I'm pissed! So I got the wheels on, and took it for a quick spin, just to see how bad it would be. Well, the runout is so bad that when I'm driving, the pads get pushed away from the rotors enough to force me to give a quick pump-and-let-go of the brake pedal prior to actually applying the brakes. Otherwise, my pedal almost sinks to the floor just moving the pads against the rotors. And if I'm braking from any faster than about 20mph, it rattles so much it feels like my teeth are going to fall out.

The rotors are the original Toyota rotors, with 70,000 miles on them, and they had only lost 0.026" in thickness. I still had 0.053" to go, which should have lasted at least another 30,000-50,000 miles if the turning was done right. Now they are garbage!

I'll be going in first thing in the morning to see what they are going to do about it.

1. I'll be asking for my $20 back.
2. I'll be asking for a new set of rotors (at least aftermarket ones) to replace the ones they ruined.

Wish me luck.

 

Update: I went in today to see about getting compensated for the shop's screw up. The only guy that was in there today was the guy that changes/rotates tires, so all he could do was give me my $20 back. He gave me the manager's name, and said to come see him monday. I then went out and bought a pair of rotors and installed them. Pulsing is gone, and all is good, but now I'm out $100. I'm hoping the manager will come through with half of that on monday. We'll see.

 

I wonder if the guy purposely messed them up?

 

I've always just sanded mine, brakes work just fine.

I have turned rotors in the past, many shops cut corners and try to surface them in one pass, meaning they'll take off excessive material. All that is needed are the high spots cut down, leaving a few low spots won't affect a thing, the pads will seat in.

 

I had forgotten about this thread. Anyways, I went in to see the manager on tuesday, armed with my before and after numbers for rotor thickness and runout. I don't think he believed that they were that far off, because he installed the rotors on the brake lathe to see how off they actually were.

He said that there's no way the rotors could be installed on the machine incorrectly (as he's tightening the cone shaped collar holding the rotor in place and tapping on the rotor to try to center it until it looks good "by eye"?!?) Hello! There's the problem, maybe? Anyways, he turns the lathe on, and brings the cutting tool against the rotor. We hear "tick...tick...tick...". He says: "hmmm, I guess they didn't do a very good job turning them."

So long story made short, they covered the cost of one rotor. In the end, I ended up with two new rotors for $50, which is OK, I guess.

 

You think for a second that they would make a mistake on purpose when a "know it all" comes in to the shop demanding work be done within his specs? Come on, no one would ever do that .

And for those that think they can turn rotors on their own, you are almost as silly as the clown who goes into a shop demaning that his rotors be turned to his specs. You can not turn rotors with sand paper. It just doesn't work that way.

 

I used to try and get my rotors turned, but honestly I have seen enough crappy equipment in shops to know not to trust them. One place I worked I could see the runout on the lathe spindle....now that's bad!!! Now a days the rotors are relatively cheap so you are better off using Bruce's sandpaper method if the rotors look pretty good (good thickness left, minimal grooving, not excessively rusted, etc) otherwise, just toss them and buy some new ones. If rotors are good, I just sand and install new pads.....if rotors are bad, replace them. If your rotors are that expensive and you want to turn them....bring them to a real machine shop where people care about tolerances and know what "runout" is.

 

Why would you even bother getting rotors turned if they are not going to come out within Toyota's specs? Any good machinist can turn rotors to within the specs Toyota allows if their lathe is good enough and if they take the time to properly mount the rotors on it.

The mickey mouse setup I saw when I went to the back of the shop with the service manager helped me find out that even though a shop advertises that they turn rotors, it doesn't mean that they have the equipment to do it right, and when I went in and asked that my rotors be turned to Toyota's specs, they should have told me if they weren't going to be able to meet that.

In any case, I have no hard feelings against that shop, since they came through in the end and did the right thing.

I agree with MTL_4runner in that next time, I will either buy new ones from the start, or I'll clean up the edges with a large flat sanding stone or something and just re-install them.

 

In some cases it takes several cuts before the rotors are true. You don't know if they are going to be in spec or not until they are true. They should have told you that they were out of spec before they gave them back to you.

Personally with the prices of rotors, I don't bother cutting mine anymore. Even if your rotors are still within spec after cutting, they are more likely to warp. It isn't worth the hassle, and I find it cheaper to replace them.

Even dearships don't bother. A lot of Toyota dealerships don't have brake lathes because it is a lot less hassle for them to replace rotors than deal with come backs.

 

You're right on all three points.
Warping is especially bad with these 4runner rotors.....unlike some other car/truck models

 

Good points!

 

I just saw this thread. Jim turned the rotors on his accord by jacking up the front, leaving it in drive and using an angle grinder. He says it worked well.

 

Obviously, you have never seen the process done. Simply put, the method I've used it on many occasions, works. In fact it takes off less material than using a lathe.

 

My 2 cents would be - find out WHY your rotors warped before repairing them and fix that problem. The reason most likely will be the rear brakes losing power - thus the higher load on fronts.

 

It could also have a ton to do with your frontend, my rear brakes were 100% and my fronts warped due to a wheel bearing going bad and bad struts.

 

0.0045" of runout is not what I would call serious warpage (remember that spec is 0.0028"). The pulsing was just beginning to be (barely) noticeable when I would brake hard. These rotors had a lot of miles on them, and were still in almost excellent condition, so I don't think there's anything that requires fixing to prevent that. Had they been set up correctly on the lathe, and had 0.010" taken off both sides of each rotor, they would have lasted me another year.

I adjust my rear brakes every oil change, so they're kept tight.

 

There is no way that you can true a rotor by hand any where close to .01 of an inch. It is simply not possible. You are out of your mind.

The next thing you are going to try to tell me is that you can eye ball your wheel alignmnet.

 

How to do your own alignment:

Link1
Link2
Link3

 

I guess I must me out of my mind...... I have done what you claim is impossible.

I've always done my own wheel alignment, won't ever let a shop touch it, got over 40k out of my last set of MTR's to prove it......

PistonSlap, the next time I sand a disc, I'll have a few fellow Yotatech members come over to observe, I have micrometers and dial indicators to measure before/after results. Then I'll let them post the results, will this be enough to prove it can be done?

 

Yeah Genius, that shows exactly how to adjust camber and caster. Quality post. Last time I checked you adjusted toe after you adjusted camber and caster. Not to mention that you can't eyeball .01" with you stanley tape measure. Yes you can get it close, but you are not going to get it 100% everytime. There is a reason that shops invest a lot of money into alignment equipment. If it was as easy as that, then they wouln't need extra equipment.