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Discussion Starter · #1 ·
I noticed a lot of rust/crud on all my brake cylinders. I suspect this is due to regeneration on a 29k mileage 2020 Rav4 Hybrid I bought recently. Has anyone any ideas about maintenance of the brakes to clean them or whether Toyota dealers will resolve this.
 

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I'm not sure what you mean by "cylinders"... the brake master cylinder is in the engine compartment and isn't an area that would rust. The calipers could be a bit rusty on the outside but that is definitely not a problem. It happens to pretty much every car over time. It is unlikely that the pistons inside the calipers would become rusty, and that's also not something you could observe without at least taking the caliper off and removing the brake pad. Based on this, I'm assuming that the rust you see is actually on the disc, or rotor. Generally speaking, a bit of surface rust isn't a problem on rotors. The rotors on pretty much any car will get a little surface rust if the car is left parked and there is a rain storm that gets them wet. Normally the pads will just "wipe" this rust off with the first application of the brakes and there's no real harm done anywhere. There may be some "grating" or "grinding" sound the first time or two you apply the brakes as that rust gets cleared off, but the sound should subside after that.

If you are getting grinding sounds from your brakes more than just the first few times you apply them, you may need to have the rotors turned, and may need new brake pads, as well. I doubt that Toyota would cover this because oxidation of the metal brake rotors doesn't indicate a material or manufacturing defect. With that said, Toyota might turn the rotors for you at no cost as a courtesy, but I wouldn't bank on that.

I suggest you go take the vehicle for a spin, do some relatively hard braking while you have it out there, maybe some braking in reverse, too (that may be the best way, actually, because I believe the regeneration system doesn't come into play when in reverse), and then see if the rust is gone.
DO NOT TOUCH THE ROTORS AFTER DRIVING - they could be very hot.

Good luck!
 

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2021 RAV4 XLE Premium Hybrid
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I noticed a lot of rust/crud on all my brake cylinders. I suspect this is due to regeneration on a 29k mileage 2020 Rav4 Hybrid I bought recently. Has anyone any ideas about maintenance of the brakes to clean them or whether Toyota dealers will resolve this.
You might want to review this T-SB for it talks about surface rust on the brake discs. The recommendation in this T-SB is to drive the vehicle at least every two months and stopping from 30 MPH at least 20 times:
 

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You might want to review this T-SB for it talks about surface rust on the brake discs. The recommendation in this T-SB is to drive the vehicle at least every two months and stopping from 30 MPH at least 20 times:
That's interesting that the TSB only covers the 2021 model year. Either they don't predict that any older models will be stored a long time or they made a change to the metals on 2021 models where rust buildup is occurring at a faster pace.

I do see that this is categorized under pre-delivery so that could be the reason for only listing the 2021 models. They may have had ones specific for the older models when they first arrived at dealers.

My first impression was hmm, why only 2021?
 

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Discussion Starter · #6 ·
I'm not sure what you mean by "cylinders"... the brake master cylinder is in the engine compartment and isn't an area that would rust. The calipers could be a bit rusty on the outside but that is definitely not a problem. It happens to pretty much every car over time. It is unlikely that the pistons inside the calipers would become rusty, and that's also not something you could observe without at least taking the caliper off and removing the brake pad. Based on this, I'm assuming that the rust you see is actually on the disc, or rotor. Generally speaking, a bit of surface rust isn't a problem on rotors. The rotors on pretty much any car will get a little surface rust if the car is left parked and there is a rain storm that gets them wet. Normally the pads will just "wipe" this rust off with the first application of the brakes and there's no real harm done anywhere. There may be some "grating" or "grinding" sound the first time or two you apply the brakes as that rust gets cleared off, but the sound should subside after that.

If you are getting grinding sounds from your brakes more than just the first few times you apply them, you may need to have the rotors turned, and may need new brake pads, as well. I doubt that Toyota would cover this because oxidation of the metal brake rotors doesn't indicate a material or manufacturing defect. With that said, Toyota might turn the rotors for you at no cost as a courtesy, but I wouldn't bank on that.

I suggest you go take the vehicle for a spin, do some relatively hard braking while you have it out there, maybe some braking in reverse, too (that may be the best way, actually, because I believe the regeneration system doesn't come into play when in reverse), and then see if the rust is gone.
DO NOT TOUCH THE ROTORS AFTER DRIVING - they could be very hot.

Good luck!
Yes not cylinders (old cars only). I am seeing rust on the rotors, but the discs
look good. So no worries.
 
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