I installed the OEM Bremos on my car about 1000km ago( see thread: https://my350z.com/forum/brakes-and-...onversion.html ) & since bedding in my brakes, my left rear rotor has looked like this:





It has criss-cross lines of brake pad residue? on it. There is no scoring or gouges in the rotor, when I touch it with my fingers its pretty smooth, you can just see that criss-cross pattern. It *seems* to be going away, I can see the regular wear pattern coming through, but I dont know what caused it. It is also happening on the opposite side of the rotor.

I have taken my pads out & inspected them, they are wearing perfectly fine & have no abnormal wear. Im just really stumped as to why this criss-cross pattern is there & how it is so perfectly done. Has anyone seen this before or have any ideas?

 

Those look like machining marks.

They're present in your just installed pics too:

 

that not an oem/brembo rotor is it? it looks like your rotor material is wearing away. if you look at your other thread, you can already see the criss cross pattern a little bit. I'd get some better quality rotors...

 

The criss-cross lines are the machine marks from where the rotors were ground flat initially. Now, they're becoming more visible as they fill with brake dust. It's all normal.

All of your rotors should have looked like that initially.

 

Thanks for the info! To be honest, my other rotors looked "normal", as in regular brake pad wear marks, pretty much right after the bed-in. At least I know its nothing irregular!

 

They are POWERSLOT rotors, sister company of STOP-TECH. The rotors are of quality. Yup, you can see the criss-cross pattern in my other pics, but its slowly fading now.

 

Yup, thats a pic from right after the bed-in & 1000km later, the marks are still there but fading. I'll take yours & Daves word that its just machine marks. It would make sense as I can't find ANYTHING else wrong with the set-up.

 

That one rotor may have been more heavily scored than the other three and now it's just more noticible. Eventually the cross-hatch pattern will be replaced by the normal radial scoring from the pads.

 

the thing that has me concerned is the rusting going on in this pic, closest to the center of the rotor...

 

although now that i look at it, just looks like some surface rust... at first it looked like it was deep rust to me for some reason... my bad

 

Its not rust, its just a build up of brake dust residue. I went & checked just to make sure. If they were rusting after 1000km, they'd be getting sent back with a nasty letter

 

/\ Ya that's just brake dust.

 

Do the brakes feel weird? Did you spray Brakeleen on them to remove the rust proof coating they come packaged with?

 

on the pic it looks kinda porous where all the brake dust is. is it actually porous or is it solid?

 

As the others said ^ It looks normal. I recall the same pattern on my Powerslots when I first installed them.

 

Yep.

 

i sure hope not...they specifically state to use soap and water and NOT brake cleaner

 

Start stepping on your brakes harder.

 

The cross-hatched grinding marks are from the manufacturing process. After turning the rotor faces on a lathe, the result is a fine spiral groove appearing fine parallel lines. To remove these unwanted grooves, rotor faces are then ground almost at a right angles (to the lathe groves) and hence the hatched markes. One gets the same results, when a shop re-faces rotors deeply scored from worn pads. Initially a lathe removes the damaged face and the rotor is then finished with a surface grinder (to remove the tool marks from the lathe). Both operation are done while the rotor spins. In short the marks on your rotors are not defects, but actually evidence that they were properly manufactured.