Thaik

Hey guys!

So basically I've just gone ahead and done a brake job. Replaced my brakes with OEM pads and resurfaced my rotors, had some grooves in them.

The thing is, after installing everything and driving a for a few hundred kilometers, the grooves started reappearing, I can feel them slightly with my finger tip, less than before, but not as smooth as the rear rotors (drum to disc swap).

My car is a Civic 2004 DX-SE (Canadian model) and the minimum thickness of my front rotors is 19mm as it is casted on them.

Thickness:
Before machining: 21mm
After machining: 20.5mm

So is this normal that the grooves are reappearing?
Should I wait for the pads to break in before jumping to an conclusion?

Thanks guys!

mikey1

ssssssoooooo.....what exactly is the problem?

small grooves in rotors are normal,

i think you are worrying over nothing,

drhawkinz

my discs always seem pretty smooth. does it pull the car left or right when you brake?

The only time I've seen a rough looking rotor was on a work truck with bad/worn out brake pads. The rotor almost felt like a record. But when you pressed the brake you had to fight the truck to keep it straight, it would make a left turn all by itself with the worn out pads.

Thaik

No, that's the thing, everything is working perfectly.

After the brake job, the braking power is even better than it was before the replacement.

I'm just trying to figure out and understand how this all works.
How the grooves were made before the brake job and why it appears again after resurfacing. The pads were pretty worn out, but not to the metal.

My brand new rear rotors are perfectly smooth.

I'm curious person who likes to understand every thing and I was just asking for your expert insight on this

drhawkinz

can you post a picture of the rotor?

ezone

How deep are the grooves you see?
Just lines visible, or actual deep scores in the surface?

Some might be normal and expected as pads and rotors both are friction and wear surfaces subject to extreme physically demanding conditions.

For instance, dirt, rocks, gravel, anything that might get kicked up off the road and find its way into the open brake areas could cause grooving.

Thaik

Although they've been resurfaced beforehand?

Here's a picture of the rotors after resurfacing.

One thing though, I've been wondering why the rotors aren't shiny afterwards while a brand new one is sparkling.

Colin42

looks plenty shiny to me

ezone

Looks like freshly turned rotors to me. I see no unusually deep grooves in the pics posted.

Do you not understand the resurfacing process using an off-car lathe?
Cutting bits make one continuous cut while moving outward, this leaves cut lines much like you would see in a record.
The first 10 minutes are all setup of the lathe, at around 12 minutes you can see how the cutting head moves during a cut