Removing paint from pad contact surfaces of coated rotors

[justalubetech]

I've used the painted rotors many times on various customer cars.... One hard stop and all the paint is gone from the pad contact surface.

The standard rotors that have the oily protective coating, bit of brake clean before install and never had a problem there either

 

[Craig in Canada]

The key is whether the pads are adherent (generally "ceramic" is this) or abrasive (generally "semi-metallic" is this). Some ceramic pads contain a gritty break in layer to cut through coatings (reference solely for the concept of a break in layer -- EBC Redstuff Ceramic)

If you use adherent pads, you should remove the coating from the swept surface, or purchase rotors which do not coat the swept surface. As pointed out, Centric sells rotors both ways.

Ceramic/adherent pads miraculously dust less because they don't grind material away while stopping. Which means they aren't great at grinding coating away either. I have read that contamination of adherent pads from these coatings can permanently affect performance, since the adherence comes from depositing a transfer layer of pad material onto the rotor. With ground off paint contaminating the surface this doesn't happen properly.

 

[nthach]

AFAIK, BMW and ATE want you to install their rotors as-is, no cleaning needed. Aisin also recommends the same, I used Dawn or brake clean to wash the protective oil. I have those coated Raybestos rotors waiting to find a home on an old Chevy C/K Blazer - I also have EHT3 pads. I’m wondering about scuffing off the coating or letting the pads do their work? They are the hybrid material.

There’s a kinda of hacky local mechanic that runs a mobile repair shop and works on the local bus fleet - he’s been installing full-coated O’Reilly BrakeBest Select rotors and their ceramic pads.

 

[Scott S]

Little off topic here, where do you get your coated rotors or painted rotors from? I need to get some brakes and rotors for my Ford Edge, looking for something that's not going to break the bank.. and I'm looking for some recommendations.. Please.. I'm looking for coated or painted so when they start to rust you don't see it through the wheels.. I'm not seeing much in a way of a matching set in RockAuto..

 

[nomas]

Scotchbrite pads ...

 

[The Critic]

Came across an older thread by @dan_erickson :

Be careful of those coated rotors!

I did a quick simple brake job on my Accord during the week and bought new rotors from Autozone. I bought the 3 year warranty rotors that are fully coated with a black paint even on the rotor to pad surface. Obviously the idea is that the pad will wear off the paint where it makes contact and...

bobistheoilguy.com

I guess it depends on the type of coating and the thickness of it.

 

[Hall]

I guess it depends on the type of coating and the thickness of it.

I use them and they are very popular around here and I'm talking about Raybestos Element3 brake parts. I'd really hope that their E3 pads don't get coating material embedded into the brake pad like the concern here is and that this is something Raybestos factored in. These rotors are coated though, not painted, but it's still a surface coating that has to go somewhere.

 

[The Critic]

I use them and they are very popular around here and I'm talking about Raybestos Element3 brake parts. I'd really hope that their E3 pads don't get coating material embedded into the brake pad like the concern here is and that this is something Raybestos factored in. These rotors are coated though, not painted, but it's still a surface coating that has to go somewhere.

Of the last 5 pairs of Raybestos coated rotors I used, 4/5 had unusually deep machining marks that are still present after a few thousand miles. And 4/5 of those cars have really noisy brakes when cold. Coincidence, no?

 

[The Critic]

Shockingly, the coating just laughs at Red Scotchbrite.

I’m trying to troubleshoot a noise issue with some Akebono pads. The plan is to try a fresh set of pads and rotors, but remove the coating before installation to prevent the remnants from sticking to the pad material.

 

[barryh]

I recently fitted new Bosch front rotors and they were painted all over. The brakes were initially very poor so much so I removed the wheels again and took off as much of the paint as I could with abrasive paper.

If someone was to fit new painted rotors all round then I would say the brakes would be positively dangerous until the paint wore off and that could take some time. I wonder what happens if you have a garage fit new painted rotors, do they bother to remove the paint. If not then the car could be considered unroadworthy.

 

[UG_Passat]

EBC has their "Brake-in" coating layer that is very abrasive to take care of the coated surfaces.

Centric has their version of it with their Mu500 layer on the PQ Pro pads

 

[Hall]

If someone was to fit new painted rotors all round then I would say the brakes would be positively dangerous until the paint wore off and that could take some time.

Have done exactly this on multiple vehicles with zero issues. The brake manufacturers simply wouldn't provide these parts if they were "positively dangerous" nor would shops install them.

 

[The Critic]

EBC has their "Brake-in" coating layer that is very abrasive to take care of the coated surfaces.

Centric has their version of it with their Mu500 layer on the PQ Pro pads

I have never used the EBC pads, but the recent PQ pros have not been great. Been getting a lot of early pedal pulsation issues.

Have done exactly this on multiple vehicles with zero issues. The brake manufacturers simply wouldn't provide these parts if they were "positively dangerous" nor would shops install them.

The issue seems to be prevalent on some pads and not others. I think it comes down to how abrasive the pad is; the Akebono also seem to have issues with keeping rust off the friction surface. So, this might be an issue that is specific to certain parts formulas. I have not had any issues with dealer pads and coated rotors.

 

[Hall]

The issue seems to be prevalent on some pads and not others.

I guess the safe option there is stick with "matched" parts, i.e. Raybestos Element 3 rotors and Element 3 pads. Same with Bosch, Centric, etc. I don't doubt for a second that these companies didn't make sure there was no issues with the paint/coating getting embedded in the pads and impacting their performance. On the other hand, they know that some people will mix pads and rotors and that would present a liability.

 

[Bfrost99]

I run an CNC line at a iron foundry. We paint all our rotors. Akebono and BMW rotors use Geo met paint while the Mercedes use solvent based paint. We are working with power stop on producing 10 part numbers, I believe all their rotors are zinc coated. The rotors after machining will be sent off to be coated and packed at a different vendor. I'll let you guys know what rotors we are producing. Currently waiting on tooling.

 

[2EHA]

The real European rotors (OE, Zimmerman, etc.) use GEOMET on their rotors.

one of these is not like the others

 

[The Critic]

I gave them a quick buzz with a roloc disc on a die grinder. No metal removed, just paint. Doing so clogged up a few discs.

 

[2EHA]

Doing so clogged up a few discs.

the worst trade deal in the history of trade deals

 

[UG_Passat]

one of these is not like the others

I didn’t have issues with Coat-Z and Akebono Euro ceramic pads

 

[UG_Passat]

I have never used the EBC pads, but the recent PQ pros have not been great. Been getting a lot of early pedal pulsation issues.


The issue seems to be prevalent on some pads and not others. I think it comes down to how abrasive the pad is; the Akebono also seem to have issues with keeping rust off the friction surface. So, this might be an issue that is specific to certain parts formulas. I have not had any issues with dealer pads and coated rotors.

As stated above no issues with Akebono with Zimmerman Coat-Z rotors.

And forgot, had Akebono with ATE rotors that had GEOMET on it

The Akebono pads in question are the Euro ceramic for me.

I had no issues with the Posiquiet pads. I did have to bed them in with about ten 60 to 5 slow downs to heat up the pad and rotors to get a proper transfer layer on it