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Hello All, I have driven just over 250 miles and am about to wash it for the first time after taking delivery. I noticed a heavy coat of brake dust on the front wheels and a lighter coat of brake dust on the rears. I thought the regen system does not use the brakes but uses the motor as the "motor" brake. Has anyone experienced this phenomenon? I've own and driven 4 different BEVs and PHEVs in the past and this is even more than the PHEV Honda Clarity which I use the brakes at every stop.
 

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2021 XC40 P8, sage green, DOM 09/20, 19” wheels, heat pump, kernel ver Jul 27, 2021, No OTA yet.
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Hi SupraTT, I have had my car since Jan and use OPD exclusively and only see the normal dirt and dust on the wheels. However, a few others on the Forum have noted problems with their brakes and especially rusting after driving in the rain. You are correct, it doesn’t seem normal.
 

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2021 Glacier Silver XC40 Recharge P8
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Hi SupraTT, I have had my car since Jan and use OPD exclusively and only see the normal dirt and dust on the wheels. However, a few others on the Forum have noted problems with their brakes and especially rusting after driving in the rain. You are correct, it doesn’t seem normal.
Ditto here. Have almost 2k miles on my P8 and have had nominal brake dust on all four wheels. but less than my ice XC60. Even with OPD the regen system still uses the brakes so you should see some dust.
 

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Ditto here. Have almost 2k miles on my P8 and have had nominal brake dust on all four wheels. but less than my ice XC60. Even with OPD the regen system still uses the brakes so you should see some dust.
If you stay within regenerative breaking range (which you can do almost all the time) how much usage of bakes do you think it uses?
 

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I have found the car engages the real brakes even under light regen, I suspect to keep the rotors clean. Maybe One Pedal mode uses them less, but I do not use OPD. When my brakes were grinding I found that even light braking the grinding got worse even though I was well within the regen range. I have no evidence, but I suspect that one of the updates made sure this happens all the time once they started getting reports of brake issues.

I have found light brake dust, but nothing like my wife's T5 when I wash them. Then again I wash frequently and my car has been in the sho a bunch and I am on my third set of pads and rotors.
 

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I have found the car engages the real brakes even under light regen, I suspect to keep the rotors clean. Maybe One Pedal mode uses them less, but I do not use OPD. When my brakes were grinding I found that even light braking the grinding got worse even though I was well within the regen range. I have no evidence, but I suspect that one of the updates made sure this happens all the time once they started getting reports of brake issues.

I have found light brake dust, but nothing like my wife's T5 when I wash them. Then again I wash frequently and my car has been in the sho a bunch and I am on my third set of pads and rotors.
I read an article, I believe it was a write up on the delays Volvo Recharge was having at port this spring when they were all delayed anyway they mentioned that Volvo had programmed in light braking to help keep the rotors clean due to brake complaints. So what you suspect is right.
 

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I read an article, I believe it was a write up on the delays Volvo Recharge was having at port this spring when they were all delayed anyway they mentioned that Volvo had programmed in light braking to help keep the rotors clean due to brake complaints. So what you suspect is right.
Do you have a link to this article. Could be interesting reading. Thanks!
 

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I saw a presentation on a dutch forum that Volvo Netherlands did that had a slide that said the brakes occasionally are cycled during regen to clean the rotors. That was probably the beginning of the year. Other than that, the mechanical brakes are also engaged at low speed and while stopped.
 

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Aah low speed. I was wonder if. About that. The grinding. Happens at very low speed.

Also yay re the cycling to clean the pads.

Good info
 

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When my brakes were grinding after seizing the grinding increased every time. I hit the brakes even lithely. Seems to me they are at least engaging them enough to keep the rotors clean. Seems like a waste of lost regen power, but it is epithet that or far more oxidation.
 

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Hello All, I have driven just over 250 miles and am about to wash it for the first time after taking delivery. I noticed a heavy coat of brake dust on the front wheels and a lighter coat of brake dust on the rears. I thought the regen system does not use the brakes but uses the motor as the "motor" brake. Has anyone experienced this phenomenon? I've own and driven 4 different BEVs and PHEVs in the past and this is even more than the PHEV Honda Clarity which I use the brakes at every stop.
Disk brake pads are always touching the rotor, its why for EV drum brakes are actually better as they can be adusted to not touch the drums. I think one of the VW's is using drum brakes on the rear for this reason
 

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ID.4 and Q4 E-Tron use rear drums to reduce drag. Volvo engages the pads with some pressure to help keep the rotors from oxidizing. Unfortunately they also use the rear as a parking brake that auto-engages when you put the P8 in Park and if there is moisture in there the pads can seize to the rotors. You can see my other posts as to how I know that.
 

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And in case anyone is wondering, no, the ID.4 doesn't perform worse than the XC40 in braking. C&D got 70-0 in 166 ft. for the ID.4 and 171 ft. for the P8.

(That was only the RWD version of the VW, so the added weight of the AWD would probably add a couple of feet. But it's clearly on par with the disk brakes in the Volvo.)
 

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ID.4 and Q4 E-Tron use rear drums to reduce drag. Volvo engages the pads with some pressure to help keep the rotors from oxidizing. Unfortunately they also use the rear as a parking brake that auto-engages when you put the P8 in Park and if there is moisture in there the pads can seize to the rotors. You can see my other posts as to how I know that.
Not just to reduce drag but also to reduce the oxidation issues you mention. Since drums are a closed-to-elements system, they work better on EVs since often brakes aren't used. All of the threads on here people complaining about rotor "seizing" has been on every EV that I've owned in the past 12 years. It is just par for the course.

Going to drums actually is brilliant especially in the rear of an EV where those brakes rarely operate. This avoids corrosion, and all the other inherent issues you/I have collectively mentioned. Over time that will also save $$ potentially. For both mfg and consumer. It is a smart move.
 

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I know VW is getting picked on for the drums, but while they may save money they have a good benefit as well. And after my problems with the P8 rear brakes I am all for rear drums.
 
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