Rotors: Replace or Turn Down?

[wolfehunter]

I went to put rear brake pads on my 2007 Accord tonight and noticed the old pads wearing uneven when I took them off. On closer inspection there are some raised areas on the rotor that are corroded and then there are the flat areas that are nice and shiny where the pads were rubbing. Heck, the inside pad was only rubbing an area about an inch wide. So before putting the new pads on I need to do something with the rotors. Can I get them "turned down" or am I just better off getting new rotors? Never replaced rotors on the Accord......is it a difficult job?

Thanks,
Scott

 

[y_p_w]

New reasonably high-quality rotors are so cheap these days that often a shop will replace them rather than resurface. It's not something you want to do yourself without specialty equipment; it needs to be done almost perfectly. The person doing it at home will probably just want new rotors, especially since they present less chance of the rotors warping and provide better performance.

 

[dparm]

Originally Posted By: y_p_w
New reasonably high-quality rotors are so cheap these days that often a shop will replace them rather than resurface. It's not something you want to do yourself without specialty equipment; it needs to be done almost perfectly. The person doing it at home will probably just want new rotors, especially since they present less chance of the rotors warping and provide better performance.



This. New rotors are cheap.

 

[spasm3]

New ones, few rotors have enough meat to be within specs after turning.

 

[901Memphis]

New rotors for sure. Rear rotors are less crucial that fronts but the nominal thickness is much smaller for the rear rotors which are probably solid non ventilated discs to begin with.

Even if they had enough thickness to turn them you still have rust issues to deal with which could unbalance the rotor.

 

[Donald]

NAPA has decent rotors for about $30 each. Spend money on high quality pads. Not rotors.

Fewer and fewer places are doing turning of rotors. You see the lathes on CL for pretty cheap.

If you have time, Amazon has decent rotors and maybe free shipping.

What do you have for a parking brake? Shoes under the hat of the rotor? If so you may need to turn the adjustment star wheel with a tool so the shoes will let the rotor come off.

If there are screws holding the rotor to the hub, you may need a hand impact screwdriver.

 

[jeepman3071]

Originally Posted By: y_p_w
New reasonably high-quality rotors are so cheap these days that often a shop will replace them rather than resurface. It's not something you want to do yourself without specialty equipment; it needs to be done almost perfectly. The person doing it at home will probably just want new rotors, especially since they present less chance of the rotors warping and provide better performance.


+1

The rotors are made in China these days, and they often aren't thick enough to be turned anyway.

 

[Quest]

chinese rotors are so cheep these days that it no longer worth my while (or the shop's time and effort) to machine them (cost way less than machining), so I'd simply get a new set of rotors during pad job and carry on with my life.

Q.

 

[michaelluscher]

New rotor's

Pick a quality brand

1. Beck Arnley,
2. Raybestos's "Advanced Technology" Line
Price shop online for OEM, If impractical

, See 1.

 

[901Memphis]

Look for mil spec balancing in the specifications and also look for painted hats so they deter rusting and corrosion.

 

[asand1]

If your pads are wearing unevenly you need to look at the condition of your calipers and sliders.

 

[951Indy]

I've given up getting rotors machined. I don't even take the thing apart unless I have all of the required parts. All four rotors and pads can be completed in the time it takes to run the suspect rotors into town and be told they're "just under spec"....

 

[Mr_Incredible]

Originally Posted By: asand1
If your pads are wearing unevenly you need to look at the condition of your calipers and sliders.


This.

WHY are your rotors/pads not seeing eye-to-eye? Inspect, clean, and lube first and foremost. Then decide what the problem is before you start "fixing" things.

But these days, I prefer to buy new rotors rather than have somebody resurface.

 

[wolfehunter]

OK, so maybe I don't need new rotors? I just wrongfully assumed that since the rotors had these raised/corroded areas on them that they needed replaced. The pads are approx 2 1/2" to 3" wide. On the inside of the driver/rear rotor the rotor is smooth/shiny only in the middle about 1" wide. The outer and inner circumference of the rotor is corroded and raised. Oddly these are the areas on the pads that are worn down. The middle of the pad has more "meat" on it where it was riding on the smooth/shiny part of the rotor. So do I need rotors or should I be checking something else?

Oh, and I did see two screws that hold the rotor to the hub but not sure about the e-brake yet.

Thanks for the assistance.

 

[stephen9666]

I also vote new rotors, but you also need to determine why the pads were wearing unevenly or hanging up. On my Sonata, the rear caliper brackets rust and the pads get stuck in place.

 

[y_p_w]

It isn't always necessary to replace or resuface rotors. I've had new pads installed with the previous rotors left untouched. There's a certain tolerance that's acceptable, even if the rotors are worn. A shop will use some kind of measuring device and might recommend keeping the rotors if they're not too thing and not warped. I had my front pads replaced without the rotors resurfaced. The only thing that looked odd was that there was still a lip of rotor material that was never touched by the pads. If they were resurfaced I believe it would have been ground down by the lathe.

 

[The Critic]

Can you post some pictures of the condition?

I usually prefer to leave them alone or resurface on-the-vehicle.

Make sure you check runout if you elect to install a new rotor. A lot of those white box Chinese rotors will exceed the specified runout limit.

 

[asand1]

New pads are often beveled at the edges. If this car is rarely driven, and has had brakes done in the last year or two the rotors may be rusting where the beveled areas are not contacting.
Rear brakes only do 30% or less of the braking and last 70% longer than fronts, this would cause long wearing and rusting of unused surface area. What is the thickness of the pads you are replacing? If they are down to a few 16ths or so then they should be evenly worn.

If you are going to try to affect a repair, replace or resurface the rotors, as you do not want the rust to contaminate or abrade the pads later. Keep in mind that resurfaced rotors have less material to resist warping.

 

[Rylan]

I'm a little surprised at these responses...

Are we really changing out rotors with the first brake pad replacement? Now I know you should not skip out when it comes to brakes, but that is wrong.

If it falls withing spec, I trust the factory rotors for at least one resurface. I keep 'em if there's no excessive rust, even wear, smooth surface, flat hub plate, spec'd thickness/runout.
Rotor lifetime also varies on pad type, vehicle weight, driving habits, racing, etc. If I need a new set, it's factory or OEM (Honda/Acura/NISSIN, Toyota/AISIN, Hyundai/Kia/AUTO7, Ford/MOTORCRAFT, GM/ACDELCO, etc.)

If the rotor doesn't need resurfacing, I usually clean up the disc surface by sanding the surface lightly by hand, or recently I was introduced to the Flex-Hone resurfacing bit for hand drills. I've been "borrowing" a friend's for cleaning up all my rotors and flywheels.

 

[SteveSRT8]

Originally Posted By: Rylan
I'm a little surprised at these responses...

Are we really changing out rotors with the first brake pad replacement? Now I know you should not skip out when it comes to brakes, but that is wrong.

If it falls withing spec, I trust the factory rotors for at least one resurface. I keep 'em if there's no excessive rust, even wear, smooth surface, flat hub plate, spec'd thickness/runout.
Rotor lifetime also varies on pad type, vehicle weight, driving habits, racing, etc. If I need a new set, it's factory or OEM (Honda/Acura/NISSIN, Toyota/AISIN, Hyundai/Kia/AUTO7, Ford/MOTORCRAFT, GM/ACDELCO, etc.)

If the rotor doesn't need resurfacing, I usually clean up the disc surface by sanding the surface lightly by hand, or recently I was introduced to the Flex-Hone resurfacing bit for hand drills. I've been "borrowing" a friend's for cleaning up all my rotors and flywheels.


As a fleet owner I am also amazed. But for years people on this forum have mistaken pad issues for rotor problems. They are often confused.

Turning rotors is simple, but has many opportunities to disappoint you. If done properly (a big 'if) it should yield a better than new finish and equal to new life. Since almost any rotor has the minimum thickness stamped right on it there is no guesswork required.

Personally I would trust a used rotor properly turned over a brand new one in a box...