Has anyone replaced the brake rotors yet?

[TC1782]

When the brake pedal is applied, regenerative and friction braking are combined to slow the vehicle. Two situations where only the friction brakes are used would be below 5mph and when braking aggressively. I would define aggressive braking as being at, or near, the point where ABS would engage.

The lone situation where only regenerative braking slows the vehicle is when coasting (while still in Drive). Four chevrons is the maximum amount of regenerative braking that can be set by the driver. That maximum setting provides light to moderate (I’m being generous here) braking force.

It would be quite challenging to drive the car while using regen for almost all of the braking.

The clarity can only Regen -55KW (I forget the specific max Regen torque, but it's in about half of the max acceleration torque). Have you ever driven a car, or the clarity for that matter? Because if you did, it should be blatantly obvious that regen can't apply anywhere near enough torque to get near ABS activation unless your in a low traction scenario. Especially at highway speeds, it doesn't take much to max out Regen on the clarity.

 

[Landshark]

Have you ever driven a car, or the clarity for that matter? Because if you did, it should be blatantly obvious that regen can't apply anywhere near enough torque to get near ABS activation unless your in a low traction scenario.

You’ve failed to understand what I said. Try reading the post again.

 

[Danks]

It has become clear here that there is some factor that causes extreme differences in the way that the rotors perform.
Specifically @insightman and now @Danks are great examples of VERY POOR corrosion performance.

Others (including myself) have experienced excellent corrosion performance with very little wear or rust.
Here is a picture of my rotors (2018, with 6 years of use, fairly low mikes - 44K miles, Garage kept in Maryland):

View attachment 23443

These rotors look practically new with no evidence of any structural corrosion.
It seems to me that this has to somehow relate to weather / atmospheric conditions where the vehicle is located.

I'm not saying that there isn't something better that Honda could have used, but the rotors are performing extremely well for many (most?) of us, and it is a mystery as to what / why this is happening to some...

For those who are experiencing this bad corrosion - Can you comment on your experience with other vehicles? Do all of your vehicles suffer from poor rotor performance? Or, is it a combination of atmospheric / weather conditions exacerbated by the relatively low brake use of the EV?

I had several Grand Am's. As I remember it the brakes would grab and grind on cold mornings after driving in rain or wet roads and then parking overnight in our garage. After just a little bit of braking the brakes were normal. I remember it happening with our Astro and GMC vans as well.

 

[MrFixit]

Look at the inner side of the rotors

I'll be changing fluids in a couple weeks and will check the inside then....

 

[Trolle]

I have to agree, I was grasping at straws to try to come up with an explanation. The fact that the OP now says that the out side of his discs are fully shiny, while the in side is a rusty mess, leads me to another guess that the in side pads are being affected by corrosion, and are sticking and therefore not applying quite as much force as those on the out side. It does seem possible the in side could get significantly rustier from road muck buildup. Did the mechanic change the pads and clean and lubricate the calipers too I hope? It would be good to know if the in side pads had less wear than the out side.

it is a issue in salty wet conditions. The inside of the rotors are close to the backing plate and the moisture in trapped in between causing significant better environment for the corrosion to take hold.

 

[Casey Martin]

I was working on my car last night so I took some pictures of the rototrs. These are the front rotors which are Raybestos Specialty Street Performance Coated rotors. Here is a link: https://www.rockauto.com/en/moreinfo.php?pk=10622856&cc=3441908&pt=1896&jsn=909
I installed them in August 2023. So they are just over a year old. I have put about 28K miles on them so far. I did resurface/cut them after replacing a frozen caliper. Overall they are holding up well for New England roads. They are slightly warped again but not terrible. I might cut them again or replace them soon. I am hard on brakes so I am accustomed to rotors warping. I might try drilled and slotted rotors next but I am not sure I want to. I haven't had great experiences with them in the past.

 

[Casey Martin]

Here are the rear rotors. These are Powerstop Evolution Geomet coated rotors. Here is a link: https://www.rockauto.com/en/moreinfo.php?pk=11908909&cc=3441908&pt=1896&jsn=903
I installed these in January of 2023. I have put about 43k miles on them. I had painted the calipers then as well. The road salt has ruined that already. I think these rotors have held up fairly well especially considering how cheap they are.

 

[MrFixit]

I'll be changing fluids in a couple weeks and will check the inside then....

Here are some photos of my original rotors (outside & inside of a front rotor, and outside & inside of a back rotor). The other two look just like these...
This is a 2018 with 44K miles (garage kept in Maryland). The rotors are practically as good as new with no signs of structural rust.

 

[TC1782]

Here are some photos of my original rotors (outside & inside of a front rotor, and outside & inside of a back rotor). The other two look just like these...
This is a 2018 with 44K miles (garage kept in Maryland). The rotors are practically as good as new with no signs of structural rust.

View attachment 23490 View attachment 23491 View attachment 23492 View attachment 23493

That's so bizarre. Mine look like trash from the inside, and the outside with develop rust rings unless I stomp on the brakes regularly. My current theory is they are just taking whatever scrap iron and slag is cheapest and just melting it down. No way we have the same rotors.

 

[NorCalPete]

Similar to MrFixit, the surfaces of my brake rotors (inside/outside, for front and rear) look practically new. This is a 2018 with 53K miles and never parked inside a garage. I'm located in northern California, so road salt isn't a factor for me. The brake pads also look virtually new.

 

[Atkinson]

Wonderful living outside the rust belt.

 

[NorCalPete]

Wonderful living outside the rust belt.

I lived in Buffalo, NY for many years, so I know how "fun" it can be maintaining cars in the rust belt.

 

[megreyhair]

Similar to MrFixit, the surfaces of my brake rotors (inside/outside, for front and rear) look practically new. This is a 2018 with 53K miles and never parked inside a garage. I'm located in northern California, so road salt isn't a factor for me. The brake pads also look virtually new.

I have a bigger version of that. I was hesitant to go that route as Honda's instruction was to pump the brakes instead of using a vac and I am sure dealers have them to do brake jobs. I guess in theory it would be the same if you wait like 30 mins after shutdown to do the other brake system. I agreed that it is hard know when the old fluids were flushed since they won't get too dark if you follow the maint reminder.

 

[David Towle]

That's so bizarre. Mine look like trash from the inside, and the outside with develop rust rings unless I stomp on the brakes regularly. My current theory is they are just taking whatever scrap iron and slag is cheapest and just melting it down. No way we have the same rotors.

More likely an error, or possibly a vendor cheating. Iron/steel is amazing stuff, but there are so many alloys for different conditions its incredible. And its hard to tell one alloy from another without detailed testing. My career was in power generation boilers, these could utilize upward of 50 different steel alloys for the tubes, welding, structure, casings etc. And the wrong variant could result in a component lasting a day instead of the 20 year design life. We were forever battling mix-ups in the shop between different alloys; once the original markings get lost in a production process it could become a guessing game.