failing rotor surface? why?

[toddmorr]

New Raybestos Element3 fully coated rotors, new Raybestos Element3 Hybrid Tech pads, Rear. Within 5 miles on a test drive I hear a rthymic slight scrape on one of the wheels at very low speeds. Maybe a dust shield is slightly scraping??? nope. Pics show a very shallow chunk of the rotor has come off, just the surface coating I guess because you can feel the very slight indentation. The other rotor has many smaller chunks off. Clearly this is a failure, probably of the fancy dancy coating. But what would cause this? Too aggressive a pad? Anybody seen this?

 

[The Cobbler]

I didn't think the coating was on the pad surfaces . it looks to me like there's porosity in the casting?

 

[Rusted Nut]

Wow, that’s 5 miles of wear? New rotors and pads? Are the pads and rotors compatible? Some of the newer hi-tech brake components (rotors/calipers/pads) can only be used with certain other compatible components.

 

[WWheeler]

Awfully grooved up looking for rotors with 5 miles on them.
Are you sure the pads aren't in backwards (unfortunately seen that before)

 

[zendriver]

Don't know about the holes, but is it normal to have those rotors that scratched up in only five miles?

 

[The Cobbler]

re the scratches , I am thinking they are painted rotors and the paint hasn't worn off yet

 

[jpaw]

From the pictures the rotors appear to be defective. The coating is to protect the rotor from rusting and to aid in seating the pads.

The coating will wear off after a few miles. If the spots are still there after a day or two I'd return both the pads and rotors for a defective part replacement. Insist that they give you new pads along with the rotors due to the debris contaminating pad material.

 

[toddmorr]

Those rotors are fully coated, meaning coated with "Grey Fusion 4.0" coating on all surfaces to inhibit rusting. You would think they would be compatible with the pads, because they're both Raybestos Element3.

 

[toddmorr]

Don't know about the holes, but is it normal to have those rotors that scratched up in only five miles?

I wouldn't think so, never seen that. Very uneven wear pattern.

 

[toddmorr]

Awfully grooved up looking for rotors with 5 miles on them.
Are you sure the pads aren't in backwards (unfortunately seen that before)

nope, on both sides the pad wear warning scraper thing is at lower inside.

 

[qqzj]

Looks like plain old poor quality

 

[yellowbox]

Porosity in the casting , take em back

 

[toddmorr]

From the pictures the rotors appear to be defective. The coating is to protect the rotor from rusting and to aid in seating the pads.

The coating will wear off after a few miles. If the spots are still there after a day or two I'd return both the pads and rotors for a defective part replacement. Insist that they give you new pads along with the rotors due to the debris contaminating pad material.

i tend to agree. Whatever fancy coating is there should be wearing evenly and not coming off in chunks like that.

 

[toddmorr]

Porosity in the casting , take em back

sounds totally plausible---porosity leads to irregular surface of the coating to attach to and therefore it fails.

 

[toddmorr]

btw, this is a plain jane 2007 Civic, nothing fancy. Never had a problem with Raybestos before but fully coated rotors was probably overkill for Maryland. Rock Auto parts.

 

[jpaw]

I don't think it's porosity, it's usually hard spots in the rotor. ****** Chinese steel.
I wouldn't be concerned if it's just the coating flaking off, it will all be gone in a few miles. However I would be concerned with the noise.

Were the matting surfaces clean, the slides cleaned and lubed, everything tight, nothing rubbing, wheels properly torqued, etc. Double check your work just to be safe.

 

[toddmorr]

Ok you guys convinced me to drive the **** out of it tomorrow. I'm curious to see what happens to that coating, whether it all comes off or not, and if it becomes a consistent surface. If it does I bet the rhythmic scraping noise will go away.

But yeah I'll take it apart in the morning to double check

 

[VolvoRyan]

Crappy steel. Looks like the machined surface, not coating.

Good luck with Rock Auto.

-Ryan

 

[jayemm]

That 'pit' in the first picture looks a lot deeper than what a coating would be. These pictures look like the coating was applied to an already pitted rotor. Kind of like the machining uncovered pits from crappy metal and then the coating hid them.

 

[gearhead1]

I agree, definitely looks like porosity.

 

[turner66]

From your picture it very much appears to be a defective casting and those are voids during manufacturing process due to impurities in the base metal. Take a pick and scrape one of those areas with the point. My guess is the point will "catch" in the void and they are much deeper than a superficial imperfection in the surface coating... I wouldn't waste my time with them. just exchange them and the pads for another set...

 

[gearhead1]

How to Prevent Casting Defects In Your Products | The Federal Group USA

Your cast iron metal pan leaves the factory with pinholes, leading to a slew of complaints from your customers. What happened? How could you have prevented

www.tfgusa.com

 

[jayemm]

I agree, definitely looks like porosity.

'porosity' Thank you. That's the word my aging brain couldn't locate last night when I posted.

 

[Buckaroo5]

Did you bed those pads in? Important to follow correct procedure. Don't just "drive the **** out of them". Look on the Raybestos site and read their recommended procedure. The coating on the face should be gone after the pads gets bedded in. That said, I am not a Raybestos fan. I used to use them but now install Powerstop rotors & pads. Have been installing Geomet coated rotors and when calipers need replaced, have been using rebuilt Cardone coated calipers. Always purchase them from Rockauto.

 

[Wolley]

That looks like the coating coming off and it balled up and attached to the rotor and smeared in. I wouldn't worry about. Id do a proper break in and keep moving forward

 

[Al Borland]

Those look like craters. Some rotors have a soft casting that is surface-treated similar to case-hardening. Sometimes, it spalls off.

 

[toddmorr]

went out today and did a proper bed-in, exactly as the Raybestos site recommended. The one rotor with the major spots gained another spot similar in size, the other rotor seemed to develop a more even wear pattern but no real change in the small spots all over it. I have to believe the issue is as many of you have suggested---a failure of the underlying steel in some way, causing a failure in the coating. OR, the coating is just garbage to begin with. Either way, RA has the pleasure of yet another warranty claim. Not a big deal....RA is good about that.

 

[finn]

It’s cast iron, not steel, and what you’re seeing is porosity. It’s a junk rotor sold with a coating that hides the problem.

Raybestos has gone through several ownership changes since they got up in the asbestos superfund debacle after years of dumping heavy metals and asbestos on the ground.

They are currently owned by an investment group and, as far as I can tell, all of their brake component production is offshore.

It’s not clear if the transmission and power train business is under the same ownership.

 

[jayemm]

Those look like craters. Some rotors have a soft casting that is surface-treated similar to case-hardening. Sometimes, it spalls off.

WOW. That's the first I've heard of this. Hope I don't unknowingly get that type of rotor. What is this type of rotor called? Thanks for posting this little nugget of information.

 

[bwringer]

Crikey, unwad your britches a little.

The rotors are painted all over, not just on the hat in the middle. (The special science word blah blah bibble babble high tech coating is... paint.)

The paint where the pads rub wears off after a while. It's fine.

In the meantime, it looks like this. It's fine.

Drive the car and find something more important to worry about, like graphing seasonal changes in the texture of your toe jam.

I've installed a couple of sets of these rotors. They're fine.

I like the paint because they don't arrive coated in greasy glop I have to clean off; I can just slap 'em on and reassemble.

 

[VolvoRyan]

Crikey, unwad your britches a little.

The rotors are painted all over, not just on the hat in the middle. (The special science word blah blah bibble babble high tech coating is... paint.)

The paint where the pads rub wears off after a while. It's fine.

In the meantime, it looks like this. It's fine.

Drive the car and find something more important to worry about, like graphing seasonal changes in the texture of your toe jam.

I've installed a couple of sets of these rotors. They're fine.

I like the paint because they don't arrive coated in greasy glop I have to clean off; I can just slap 'em on and reassemble.

The coatings are kinda nice since they protect the "outer rim" a bit. Still, these pits are well into the machined surface of the rotor.

Are you a service manager? Because you sound like the dealership that told a guy there was nothing wrong with his front suspension after they did struts. Hard steering with a moan. I opened it up and found that a strut bearings was non existent. Well, it was there... but it no longer functioned as a bearing. Looked like it came apart on the installer who neglected to put it back together.

-Ryan

 

[bwringer]

If those black spots in the OP's photo are pits in the casting, then obviously that's a problem.

If they're globs of scraped and burnt paint, which is what I think they are, then it's not a problem.

OP needs to get something sharp and poke them to see what the black spots are.


And no, I'm not a service manager... just someone who has recently installed two sets of these very rotors and noticed the same thing. I thought nothing of it, since I knew the coating was some sort of paint. It's messy for a while as the paint wears off (and the flakes of paint are a little messy), but they look fine now and work perfectly.

 

[zendriver]

To keep disc brake contact surfaces from prematurely failing due to corrosion, they are "coated'" with a material that wears off soon after installation.

Wonder what Forrest Gump would have to say about this?

 

[Old Man Roger]

Zoom in on the pictures, those things are junk.

 

[Wrench97]

Return them they are junk

 

[toddmorr]

rest assured, those larger spots are indentations in the coating--coating that has chunked off, so to speak. It ain't paint or anything else that's in globs stuck there. Since I went back to bed them in exactly as Raybestos recommended I can see most other areas of the rotor coating that are now slightly wearing in a nice even way. As you would expect. Kind of raises the question as to what happens when the coating is entirely worn off....what was the point of having it on there to begin with.

Anyway, it makes complete sense to me that some fault in the underlying iron caused a problem with the coating adhering. OR that the coating itself is defective. Either way i'm not messing with totally coated rotors again.

 

[The Cobbler]

my so called ceramic coated rotors that I just installed didn't have coating on the wear surfaces

 

[Old Man Roger]

rest assured, those larger spots are indentations in the coating--coating that has chunked off, so to speak. It ain't paint or anything else that's in globs stuck there. Since I went back to bed them in exactly as Raybestos recommended I can see most other areas of the rotor coating that are now slightly wearing in a nice even way. As you would expect. Kind of raises the question as to what happens when the coating is entirely worn off....what was the point of having it on there to begin with.

Anyway, it makes complete sense to me that some fault in the underlying iron caused a problem with the coating adhering. OR that the coating itself is defective. Either way i'm not messing with totally coated rotors again.

The coating on the friction surface is only there to keep it from rusting during shipping and storage, it’s meant to wear off under normal braking. The problem is the pits in the cast iron.

 

[d.mcfarland]

Kind of amazed this argument is still going on to be honest.

 

[zendriver]

Kind of amazed this argument is still going on to be honest.

How long have you been a member here?

We haven’t started arguing about EV regenerative braking yet so there’s plenty of time.