Brake disks - Safe?
 

I just got a pair of new disks for the MB100 and went to fit them today. One disk was fine but the other has a chip out of it. It's about 4mm deep and within the swept area of the pad.

My feeling is that it's safe to use, though not ideal obviously. I bought them off a eBay retailer so returning/replacing them might be a pain, and I need to get them on during the new year break. I've already fitted one new disc, so I'm thinking just fitting new pads to the other side and waiting for a replacement might be an option?

Thoughts and opinons sought ;)

Trim it down with an abrasive so it does not protrude and cause a shudder (pulsation). I would use a file and dress it down.
Should be fine otherwise.
regards
Mech

Generally I have seen that pads run a bit inboard of the edge of the disk. I would feel pretty comfortable following old mech's advice.

The only thing I would be concerned with is the possibility of a hair line fracture developing at or near the chip. If you do a through job of blending and smoothing it should be a fairly minor risk. So inspect it pretty soon after you get it rolling(pads worn in), then take a good look after a few thousand miles and again when you rotate the tires.

As said, being on the outer edge it wont make much difference if any. As long as there aren't any raised portions it'll be fine.

A chunk like that missing from a piece that is supposedly a solid casting would give me pause. A chunk like that missing from a casting upon which I rely like I do the brakes in my car...

...I'd return them for a refund. Brake rotors matter too much to take risks.

To me this is one more reason to stay away from eBay brake rotors. The previous owner of one of my (now former) cars had put eBay slotted/drilled rotors on the car. The material itself was garbage. I never saw anything rust so fast in my life.

Follow Old Mech's advice. You'll be ok.
 

Edge damage is far less problematical than interior damage in rotating machinery. I've had disks far more severely damaged than that finish 35 lap sprint races at the old Riverside Raceway.

I do agree that these Chinese made disks are of lower material quality, but the fact that they rust is not a good indicator of this.

They came off eBay, but they're PBR branded. The original rotors only went ~50K miles (warped when I bought the vehicle) so I wasn't going to pay the silly money the dealer would want, and even the local parts shop wanted $400+ for TRW discs.

A lot of the name brand parts come from China anyway so really it's just pot luck.

You raced Riverside. Now I'm just plain jealous.
You both make a good point. I should have specified that the rotors I watched rust before my eyes were off-brand parts. And I do understand that unfinished cast iron will rust no matter what, but the rotors I had were exceptionally good at it. For example the vented front rotors were no longer vented due to rust that built up up like a fungus and clogged them solid.
I think it's more a matter of quality control than source country. Honda, Toyota and lots of other Asian manufacturers manage to source perfectly good, high quality stuff from China. But a lot of pure crap comes from there too.

Id return them and get a set of cross drilled and slotted ones. Better yet, get a set of ceramic pads to match. :thumbup:

Seriously, its on the edge, I wouldnt worry or do anything but install them, pump your brakes a few times to firm the pads up before driving off. If it was inboard where the friction material touched, maybe.

I would run with them, and not be too concerned.

In the meantime, I would contact the seller and ask for a refund/replacement. This is obviously there fault, and if they are a reputable seller they will want to make this right, rather than risk negative feedback. If they are not reputable, then you are out of luck, but it was worth a try.