Brakes question

[Rigger]

I'm kind of a brakes noob; I have a question for you all.

Context: A couple years back, I rebuilt brakes on an FJ40. I bought a new set of front rotors for it. A guy at the local brake shop recommended attaching the new rotors to the wheel hubs and then lightly surfacing the rotors to "true the rotors to the hubs". It kinda made sense to me, so I had him do it.

I am going to replace the brake rotors on my new-to-me '03 Hundy. Did any of you that have done brakes on your trucks do this surfacing? When you install new rotors, do you need to turn them to true them to the hub? I've gone thru some brakes threads here and no one has mentioned doing it.

I'd like to buy either some Brembo rotors or those ones that Slee sells. I intend to do the work myself.

Thanks.

 

[Trunk Monkey]

I've never heard of truing rotors on a car, only on bikes or motorcycles. He may have been talking about machining the surface off vehicle. I wouldn't worry about it on the 100, I would worry more about properly bedding the new rotors and pads.

 

[Anthony.L]

Nope, pop the old ones off and the new ones on. Zero issues.

 

[APKhaos]

^ +1
The very idea of "needing to true" new rotors is bogus.
When replacing rotors its important to clean up the mating surface on the hub with a wire brush or wheel to remove any corrosion etc. That ensures that the new rotors sit flush when installed. Nothing else required.
Replacing rotors on race cars is a regular operation - maybe 3 or 4 sets a season on some cars. Braking performance is critical, and we don't ever see new rotors "out of true" as your guy claimed.

 

[agaisin]

I've heard of it before - but I believe it really boils down to compensating for one of three other real problems:
1) hub face not true - i.e. it has some 'high' or 'low' spots
2) mating surface not clean
3) rotor is not true out of the box

If you realize the mating surface needs to be clean from debris (we're talking thousands of an inch matters here) you'll be more careful when putting everything back together. If you are concerned you could use a dial indicator after it's together to see if there's a problem or not.

If you have a problem - that's where you might want to decide it's not worth the hassle of tearing it down, tracking down the problem b/c at that point aside from time/labor you might be looking at replacing the hubs or having to exchange the rotors. It's easier to just get them turned for probably what like $20 a wheel or less and 'know' that they're 'true'.

That's my take on it at least.

 

[Rigger]

I sort of forgot about this thread, so am gonna update:

Brought the truck to a shop, and asked them to look at the brakes. They said they needed to turn the rotors. The quote was pretty high, I thought. He explained that the bearing repack alone was 4 hours of labor. Hmmm.

Brought the truck to the Toyota dealer. Much better quote. They put on all new OEM hardware. They turned all the rotors; did 'em right there on the truck with some special machine, I guess. Total tab; less than $600. Truck stops beautifully; no more pulsating brakes.

I'm happy with the technician. He did a nice job for me. I later went back and had them change oil, change wiper blades, air filter, and a few other things.

I'm really liking this truck now.

 

[GaFJC]

Before moving, I had a mechanic I used for over ten years and only had one issue with a repair that required me to return the car (a heater motor that failed after nine months - they replaced w/o question).

They turned new rotors before installing and it sold me on doing it.

I had them to do this with rotors I purchased from a Mud vendor after developing a problem with a vibration. They did them on the 100, didn't remove the rotors in this case. Yes, the hub surfaces were clean - no dirt or corrosion - it's a clean southern truck. Yes, the rotors and pads were bedded properly.

Haven't had a issue with them since.

Some rotors do indeed come out of the box and need to be trued. Others do not.

 

[SWUtah]

I sort of forgot about this thread, so am gonna update:

Brought the truck to a shop, and asked them to look at the brakes. They said they needed to turn the rotors. The quote was pretty high, I thought. He explained that the bearing repack alone was 4 hours of labor. Hmmm.

Brought the truck to the Toyota dealer. Much better quote. They put on all new OEM hardware. They turned all the rotors; did 'em right there on the truck with some special machine, I guess. Total tab; less than $600. Truck stops beautifully; no more pulsating brakes.

I'm happy with the technician. He did a nice job for me. I later went back and had them change oil, change wiper blades, air filter, and a few other things.

I'm really liking this truck now.

I too got lucky and have a local Toyota dealer that does great work for the right price. They just did my repack and new pads and hardware all around. I was careful and bedded them right and should be good for another 50k miles.