Grooved rotors

[K4fxd]

I have yet to find a shop willing to touch them and take on the liability.

Take them to a machine shop, not autozone.

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[K4fxd]

You put the lathe on the slowest feed setting and make light cuts.

Which shouild be done even without grooves. You get a better finish. I've seen some turned rotors that looked like LP's.

 

[UnhandledException]

Your old pads will wear groves into the new rotors so yes new pads also.

I am not going off track car specs I am going off passenger car norms for brake component life and wear which is why I think its time to change. You're within a few thousand, miles of the upper limit for regular cars and performance pads are harder on brake rotors regardless. Cross drilled rotors don't last as long as solid rotors, its a daily for you but its still performance parts.

There is no way to fix the pads? They are brand new:(

 

[Point45]

There is no way to fix the pads? They are brand new:(

Not in any practical manner, new pads or risk the new rotors. Its cheap is the grand scheme.

 

[tec548]

I wish people would quit spreading myths.

You can turn drilled and slotted rotors.

These are semi floating... you cannot resurface these rotors. Well, do what you want but they will not come out true.

 

[K4fxd]

The pads you have on now will get grooves that match the rotors. If the rotors are in spec and you have no vibration and it stops, I'd let them wear out. Next time, if you still have the car do both, pads and rotors.

 

[K4fxd]

Wrong, errr technically you are correct. They can be taken apart and put on a surface machine. Might cost a couple of hundred dollars each but cheaper than new rings.

 

[Wildcardfox]

Not the groves but look at the lip at the edge of the rotors. It LOOKS to be well over 1mm on just that side.

if the lip really is .35mm shallow then just keep running what you have, I wouldn't even bother surfacing them at this point but when you get new rotors get new pads as well

I’m going off of his measurements of “Front rotors are around 35.5 mm and rears are 26 mm”, that’s adequate thickness and above the min requirements, so turning will flatten the surface. Based on that information, turning would be a cheaper solution as it is an option.

And new pads are a must regardless of whichever solution he chooses, turning or replacement.

And let me add, if you take a set of rotors to a brake shop to be turned, they will measure the thickness and check the stamping on the rotors for the min thickness, so looking at a picture or even a person measuring them doesn’t matter, they will use their calipers to check that there is adequate material to turn the surface.

I used to build big brake kits and multiple take off rotors would come with the caliper package, and we would have them turned if they were above the min thickness. Many had grooves or a lip and after turning were a perfectly flat surface.

OP take them to get turned.

 

[honeybadger]

Rotors and pads are fine as long as they’re above the minimum thickness. Surprised to see so many thinking this is a throway scenario.

Also, you can absolutely get those rotors turned. I’ve done a few. A local Napa in the PNW did mine a few times.

 

[K4fxd]

Rotors and pads are fine as long as they’re above the minimum thickness. Surprised to see so many thinking this is a throway scenario.

Also, you can absolutely get those rotors turned. I’ve done a few. A local Napa in the PNW did mine a few times.

Yea, it is the floating rotors that pose a problem, but that is solved by a surface grinder.

 

[Point45]

I’m going off of his measurements of “Front rotors are around 35.5 mm and rears are 26 mm”, that’s adequate thickness and above the min requirements, so turning will flatten the surface. Based on that information, turning would be a cheaper solution as it is an option.

And new pads are a must regardless of whichever solution he chooses, turning or replacement.

And let me add, if you take a set of rotors to a brake shop to be turned, they will measure the thickness and check the stamping on the rotors for the min thickness, so looking at a picture or even a person measuring them doesn’t matter, they will use their calipers to check that there is adequate material to turn the surface.

I used to build big brake kits and multiple take off rotors would come with the caliper package, and we would have them turned if they were above the min thickness. Many had grooves or a lip and after turning were a perfectly flat surface.

OP take them to get turned.

Agreed if they're above minimum.

The shop will know, just in my experience 1mm is about the limit for wear and the pics look like over 1mm. I do ALOT of machining and that lip looks over 1mm but it is just a pic.

But it LOOKS close enough to where I personally would have just gotten new rotors when he replaced the pads recently. As I said, if its in spec for thickness and he current pads are working/bedded I would just leave as is and swap it all out next time.

 

[WD Pro]

I don’t think those grooves are typical brake disk grooves from uneven wear / debris etc that lead to the ‘replace’ conclusion.

I think they are just an effect caused by the particularly long life seen on that set of rotors and that it’s a natural pattern caused by the drilling - they look far to uniform to be from debris and appear to line up perfectly with the drill positions. I have had similar on road use only drilled disks.

If it were me, so long as a good inspection reveals no defects and the thickness is good, (for your kind of usage) I would say you are good to go

WD

 

[UnhandledException]

Thank you guys. What is the rotor thickness for front/rear for brand new rotors vs minimum thickness?

 

[UnhandledException]

I used a different caliper to measure the rotors and they turned out to be lower, around 34.6-34.7mm. The first caliper I was using is flat on its measuring surface which was making it difficult to get accurate measurement due to that lip. I bought another one from HF that is indented. The lip is also around 0.5mm per side.

The rears are 25.9mm.

The reason I ask for what these rotors measure new is to figure out how many mm I use up per 5k miles or so. Does anyone know the thickness when these rotors are brand new?

 

[honeybadger]

I used a different caliper to measure the rotors and they turned out to be lower, around 34.6-34.7mm. The first caliper I was using is flat on its measuring surface which was making it difficult to get accurate measurement due to that lip. I bought another one from HF that is indented. The lip is also around 0.5mm per side.

The rears are 25.9mm.

The reason I ask for what these rotors measure new is to figure out how many mm I use up per 5k miles or so. Does anyone know the thickness when these rotors are brand new?

Minimum thickness is usually stamped on the rotor hat

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