Should rotors be replaced in pairs?

[The motor guy]

I'm down to metal on metal on one of my rotors.....ooops Any reason why I can't just replace just that one front rotor and leave the other one alone? Still plenty of thickness on the rotor, it just made the surface a tad rough.

 

[CharBaby]

Do you mean you’re down to metal on one of your pads? Rotors are all metal so you’re always down to metal on those.
I suppose you can replace just one rotor but it might be more time-consuming when you have to replace the other since you’re already doing your brakes. Or are you only replacing a rotor and that’s it…not the pads too?

 

[shortyb]

What vehicle and what do the rotors cost? I'm not a big fan of turning a rotor, rather buy a new one. Skimming is ok I guess as long as it's a light skim to clean the surface. Are you also replacing pads? I would assume so due to metal/metal. My opinion would be to replace rotors and pads then break everything in together instead of trying to mix and match. Eat the added cost for safety and the education of checking pads more often.

 

[The motor guy]

Do you mean you’re down to metal on one of your pads? Rotors are all metal so you’re always down to metal on those.
I suppose you can replace just one rotor but it might be more time-consuming when you have to replace the other since you’re already doing your brakes. Or are you only replacing a rotor and that’s it…not the pads too?

I'm replacing the pads, the pads on one wheel wore down to the backing plate, so I'm metal on metal.

 

[eljefino]

Whatever your new pads are, you shouldn't install only on one side, as the friction coefficient could be different from the other side and cause a pull.

New pads on well used rotors aren't a great idea-- yeah, they'll eventually conform to the grooves and work ok. The "rules" about "pad slaps" apply.

But if your other rotor is decent, yeah, leave it if you need the money.

Whatever the reason you went metal on metal should be addressed, if it was a sticky caliper or sticky pins. If you have sticky pins on one side you should clean and lube the other as well.

 

[shortyb]

How did one side wear faster than the other? Are the sliding pins sticking on one caliper causing binding?

 

[The motor guy]

How did one side wear faster than the other? Are the sliding pins sticking on one caliper causing binding?

probably. I haven't taken it apart yet. The other side is only at the little screecher tab thingy. I have a diesel so I never hear anything until I'm down to the metal

 

[The Critic]

I have a diesel so I never hear anything until I'm down to the metal

Sounds like someone doesn’t have a proper preventative maintenance program in place - worn brakes should never be a surprise if you rotate the tires and inspect the brakes every 5K.

 

[Chris142]

Every shop I ever worked at would only replace rotors as needed . Plenty of times I have only replaced 1 rotor.

 

[The motor guy]

Every shop I ever worked at would only replace rotors as needed . Plenty of times I have only replaced 1 rotor.

Should I replace the rotor if I ran it down to the back plate on the pad? Still has plenty of thickness left. I know one time we didn't have a rotor and just put pads on anyways, and never had any issues with that one wearing more.

 

[Jdeere562]

Sometimes factory rotors still have more "meat" on them after being turned down, than the China replacements do new.

 

[Passport1]

Back during the Jurassic era when I was a mechanic I turned lots of rotors. Most of the time when properly cleaned up they were close to the minimum allowed. Once you take that much meat off the surface it will warp easier.

I'd only replace rotors today. They are mission critical.

Wagner Brake

 

[The Critic]

Sometimes factory rotors still have more "meat" on them after being turned down, than the China replacements do new.

Internet myth.

 

[slacktide_bitog]

Yes, they need to be replaced in pairs!

If both sides aren't wearing equally, you have a problem with one of your calipers. The side that isn't worn probably has a frozen piston or something.

 

[andyd]

My blue Camry has been riding around on an Auto Zone caliper and pads for 2yrs/30K miles. I ignored the noise, too long, and the trouble was a stuck caliper slide, After I replaced the bad stuff, I proactively took the calipers off and re-lubed all the slides with Syl-Glide.Stops fine

 

[ron17571]

I would replace both sides.

 

[John105]

I would replace both sides and always have, but when my wife got a screw in one tire, Costco said we could only replace one, not 4. At the time I was hemming and hawwing will this ruin the ABS or AWD or stability. I've long since forgotten that only 1 is new. So probably 1 rotor is ok too if we're on a low budget be it money or time.

 

[Chris142]

Should I replace the rotor if I ran it down to the back plate on the pad? Still has plenty of thickness left. I know one time we didn't have a rotor and just put pads on anyways, and never had any issues with that one wearing more.

The rough side needs to be turned first. Then if it's above min spec it's ok to use

 

[Bullet]

probably. I haven't taken it apart yet. The other side is only at the little screecher tab thingy. I have a diesel so I never hear anything until I'm down to the metal

 

[Bullet]

Yes, you will have uneven braking power.