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Are you seeing this? (Excessive rear brake dust)

Are you seeing excessive brake dust in the rear?


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Black306

Black306

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Two things can cause more that the typical nearly non-existent brake dust:

1) Use of the brake pedal (usually due to approaching stops too suddenly for regen only braking)

2) Brake calipers in need of cleaning/lubing. This doesn't need to be done regularly in most driving environments but driving through de-icers or alkaline dry lake beds/alkaline dust can cause surface corrosion on the caliper pins which can prevent the brake pads from retracting as designed. A clean and lube of the calipers will fix it.

Edit: Having inspected your photos more closely, it looks more like surface rust of the discs from lack of use, than brake pad dust. If the truck is parked out in the rain, or driven in the rain, an occasional one second moderate application of the brakes at 40-60 mph should clean off that rust in a manner that allows it to just blow away. If you don't do that, the automatic brake application when approaching a stop will rub the rust off onto your wheels (because you are going so slow).
1) I don’t drive the CT aggressively to require regular use of the brake pedal. When I noticed this issue, I’ve even tried to be more gradual on deceleration to help reduce reliance on the brakes.

2) Other than a trip to Yosemite for a few days, and even then snow fall was minimal, this truck is driven around Sacramento which has mild weather.

Hasn’t rained in 6+ weeks and Sacramento is considered a dry climate; rust isn’t typically an issue. CT is driven daily, so rust doesn’t have a chance to build up. Plus, rust on rotors isn’t a problem on the front brakes, or the brakes on any of my other cars.
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HaulingAss

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1) I don’t drive the CT aggressively to require regular use of the brake pedal. When I noticed this issue, I’ve even tried to be more gradual on deceleration to help reduce reliance on the brakes.

2) Other than a trip to Yosemite for a few days, and even then snow fall was minimal, this truck is driven around Sacramento which has mild weather.

Hasn’t rained in 6+ weeks and Sacramento is considered a dry climate; rust isn’t typically an issue. CT is driven daily, so rust doesn’t have a chance to build up. Plus, rust on rotors isn’t a problem on the front brakes, or the brakes on any of my other cars.
It's not the snow or cold temperatures that are the problem. Warm temperatures actually increase the rate of corrosion. You do need water, but it doesn't have to be liquid, simply humid air is enough, especially if there are contaminates on the metal that promote corrosion. These can come from alkaline soil dust, industrial pollutants, deicers on mountain passes, acid rain, vehicular exhaust, etc. And Sacramento does get significant rain 5-6 months in the fall/winter/spring.

Finally, discs come in different alloys, depending upon the application and what the manufacturer selects. Higher performing discs have higher iron content and rust very easily. Usually these are reserved for performance applications where rust is not a consideration. As the alloys become more corrosion resistant, their braking performance suffers, requiring bigger rotors to do the same job. Some manufacturers prioritize rust free discs at the expense of performance or having to use bigger, heavier rotors to get the same performance.

Also, ICE cars rarely have much rust on the rotors because they lack regenerative braking and are regularly cleaning the rust off the rotors at higher speeds where most of the rust can blow away. Regenerative braking doesn't work as speeds approach zero so much of the rust is scrubbed off at very low speeds where more of it can deposit on the wheels.

After inspecting your photos, and knowing that you rarely brake hard, I think what you are seeing is more rotor rust than brake pad dust. As I previously mentioned, occasional brake application at higher speeds can help minimize the rust deposited on the rims.
 
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Still ain’t buyin’ what you’re sellin’. My driving style doesn’t significantly change between cars, very recent weather since I’ve last cleaned the rims is less prone to rusting metal, and I doubt the metallurgy on CT rear rotors is so vastly different that it causes such a difference in the rear brakes of a CT.

That said, I’ll experiment. If the rims still get dirty after changing the brake/regen setting, I’ll change my commute to include more high speed braking. But I’m going to give time for the setting variable to play out. Don’t want to introduce more than 1 variable. ?



EDIT: Rethinking this. I think we're splitting hairs. Going back to my original comment/question, there is an excessive amount of rear brake dust. Whether from pads or rotors, it doesn't matter. In my observation, there is an over reliance on the rear brakes. If I was able to set the CT to Roll mode, this would not happen since (1) brakes would be applied sparingly to maximize regen and minimizing brake dust generation, and (2) brake force would be applied to all 4 wheels and most of the braking force would come from the front brakes.
 
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Two things can cause more that the typical nearly non-existent brake dust:

1) Use of the brake pedal (usually due to approaching stops too suddenly for regen only braking)

2) Brake calipers in need of cleaning/lubing. This doesn't need to be done regularly in most driving environments but driving through de-icers or alkaline dry lake beds/alkaline dust can cause surface corrosion on the caliper pins which can prevent the brake pads from retracting as designed. A clean and lube of the calipers will fix it.

Edit: Having inspected your photos more closely, it looks more like surface rust of the discs from lack of use, than brake pad dust. If the truck is parked out in the rain, or driven in the rain, an occasional one second moderate application of the brakes at 40-60 mph should clean off that rust in a manner that allows it to just blow away. If you don't do that, the automatic brake application when approaching a stop will rub the rust off onto your wheels (because you are going so slow).
Hmm, only the rear discs rust?
 


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I am seeing this too with less than 500 miles since purchasing and DON'T love it. A major Tesla selling point is never having to do a brake job.
My thought is FSD (which I DO love and use 90% of the time) is using brakes way more than I do when one-pedal-driving. I had the same observation with my Y and 3. They would come in hot to stop signs, turns, slowing traffic ahead and then apply brakes when regen didn't accurately account for the closing distance.
I submitted a suggestion to Tesla to have a "Zen" FSD option, lower than Chill, that would maximize range/efficiency like one-pedal-driving and ELIMINATE brake use except in emergency maneuvers. Think like a hyper-miler. I imagine that can certainly be done. Patiently waiting.....
 

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More than likely, it's disc rust. It gets scrubbed off when the brakes are activated. Most drivers apply brakes when still at a high rate of speed so the dust is blown clear. EVs typically can use regen right up to stop. We all know these things. However, the CT is heavier than most cars and when coming to a stop, must use the brakes more often to complete the stopping motion. Tesla favors the rear brakes (I've read here) for this action probably because it causes less nosedive as you stop making it feel like a more premium ride.

I'd be willing to bet your brake dust is primarily just one of the two back tires. On mine, it's the driver's side.

As a side note, my last F-350 was also a notorious disc dust demon... But, only in the front.

The probable solution is to try to feather the throttle as you come to a stop in an effort to "fool" the regen from utilizing the brakes. Then, as some have suggested, occasionally apply slight brake pressure while at speed.
 
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Sxksxk

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The technician at tesla service. Told the vibrations I feel between 40 and 50 mph. Was from the truck using the brakes while regen was active. I think I will try turning that setting off to.
Is the vibration max at like 45mph and 30% into regen?
 
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More than likely, it's disc rust.
Whether the dust comes from pads or rotors doesn’t matter, IMO; brakes are exclusive, if not heavily biased, to the rear. My ideal solution would be to have Roll mode, which [unfortunately] isn’t an option on a CT. My 3s are in Roll mode and don’t have this issue cause I’ll use regen down to ~5-10mph then press the brakes. And when I press the brakes, pressure is applied to all four corners minimizing buildup only in the rear.

Next best, system should use the brakes normally by applying the brakes to all 4 corners.

I'd be willing to bet your brake dust is primarily just one of the two back tires. On mine, it's the driver's side.
For me, both rear sides pretty evenly.


The probable solution is to try to feather the throttle as you come to a stop in an effort to "fool" the regen from utilizing the brakes.
Tried that. Didn’t seem to help. Hard part is knowing when the brakes are applied. I find the transition is imperceptible.

Roll mode is available in off-road mode. I’m tempted to drive around in off-road regularly. Problem is that the lowest ride height is High and I prefer to drive around in Low. 1st world problems. 😁

I have been having the brake dust issue for over a year now. Saw your post and mine was on. So thanks for the advice, hopefully it works.
That’s was my test. Normally have ā€˜Apply Brakes When Regenerative Braking Is Limited’ turned off. But tried cleaning the rims, turning on the setting, and drove normal. Brake dust is still a problem.
 


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I rarely use brakes... I'm so used to regen I'm not sure I'll ever change the pads. Useless FSD uses them more...
 

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I’m thinking of ceramic-coating the wheels to make them easier to clean. But I’d need to get them clean first!

I just scrubbed the wheels twice, and used IronX, but they’ve still got ruddy deposits. I guess I’ll need to become ā€œthat guyā€ and get an electric toothbrush just for detailing šŸ˜
 
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I’m thinking of ceramic-coating the wheels to make them easier to clean. But I’d need to get them clean first!
Coleton must be a forum member.

 
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