Brake Sensor

nbay89 · 02-23-2021, 08:44 AM

Is there an actual brake sensor that will trigger a dash light once brake pads are worn and due for change? I know the vehicle info on the dash gives you a mileage until they are "due" to be changed. Wasn't sure if this is an estimate from when they were last changed or actually something the car can sense. TIA

Fliplegend · 02-23-2021, 09:10 AM

Yes. There's one for the front and one for the back. It's basically a closed loop system and once the brake pads are low enough, it exposes the sensor to the rotor. Once it makes contact with the rotor, it's no longer closed and triggers a light along with a countdown.

The info on the dash is merely a guesstimate.

nbay89 · 02-23-2021, 09:22 AM

Perfect. Thanks so much!

Billfitz · 02-23-2021, 12:04 PM

Not so fast. There's a sensor on the right rear inside pad and the left front inside pad. That leaves the other six pads unaccounted for. There's still no substitute for a yearly visual inspection of all eight pads.

Fliplegend · 02-23-2021, 12:31 PM

Quote:

Originally Posted by Billfitz

Not so fast. There's a sensor on the right rear inside pad and the left front inside pad. That leaves the other six pads unaccounted for. There's still no substitute for a yearly visual inspection of all eight pads.

Correct. And in my case, the inner pad wore out faster so just visually inspecting the outer pad without removing the wheel may give you a false sense of pad life.

johnung · 02-23-2021, 12:41 PM

Quote:

Originally Posted by Fliplegend

Quote:

Originally Posted by Billfitz

Not so fast. There's a sensor on the right rear inside pad and the left front inside pad. That leaves the other six pads unaccounted for. There's still no substitute for a yearly visual inspection of all eight pads.

Correct. And in my case, the inner pad wore out faster so just visually inspecting the outer pad without removing the wheel may give you a false sense of pad life.

Ah, life was so much simpler when the metal on metal grinding was the indication that it may be time to take a look at your brakes! 😀

Fliplegend · 02-23-2021, 12:46 PM

Quote:

Originally Posted by johnung

Ah, life was so much simpler when the metal on metal grinding was the indication that it may be time to take a look at your brakes! 😀

or when your brakes were your Flinstone feet!

heifetz17 · 02-23-2021, 08:07 PM

Generally speaking if your inner pads are wearing more than a few millimeters than your outer pads you probably have something wrong. BMW has used sensors in the inner pads since at least the 80’s, and it does give you a good sense of pad life. Both sides of the axle should be wearing the same, and the inner should only be a few millimeters more worn than the outer, so you don’t need sensors on all four wheels.

Billfitz · 02-23-2021, 10:03 PM

On the other hand...https://f30.bimmerpost.com/forums/sh....php?t=1471617

02-23-2021, 08:44 AM	#1
nbay89 Private First Class 70 Rep 156 Posts Drives: 2016 435i xdrive Coupe M sport Join Date: Feb 2020 Location: Pennsylvania iTrader: (0)	Brake Sensor Is there an actual brake sensor that will trigger a dash light once brake pads are worn and due for change? I know the vehicle info on the dash gives you a mileage until they are "due" to be changed. Wasn't sure if this is an estimate from when they were last changed or actually something the car can sense. TIA
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02-23-2021, 09:10 AM	#2
Fliplegend Captain 1471 Rep 975 Posts Drives: 2015 435ix F33 Join Date: Nov 2018 Location: NH iTrader: (0)	Yes. There's one for the front and one for the back. It's basically a closed loop system and once the brake pads are low enough, it exposes the sensor to the rotor. Once it makes contact with the rotor, it's no longer closed and triggers a light along with a countdown. The info on the dash is merely a guesstimate. __________________ 15' 435i F33 Metallic Grey/Dakota Black/Contrast Blue \| AWD \| M Sport 15' 328i F30 Mineral White/Dakota Saddle Brown \| AWD \| Luxury Line
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02-23-2021, 09:22 AM	#3
nbay89 Private First Class 70 Rep 156 Posts Drives: 2016 435i xdrive Coupe M sport Join Date: Feb 2020 Location: Pennsylvania iTrader: (0)	Perfect. Thanks so much!
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02-23-2021, 12:04 PM	#4
Billfitz Lieutenant General 8221 Rep 16,054 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	Not so fast. There's a sensor on the right rear inside pad and the left front inside pad. That leaves the other six pads unaccounted for. There's still no substitute for a yearly visual inspection of all eight pads.
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02-23-2021, 08:07 PM	#8
heifetz17 Second Lieutenant 90 Rep 234 Posts Drives: 2013 328xi Join Date: Oct 2020 Location: Montana iTrader: (0)	Generally speaking if your inner pads are wearing more than a few millimeters than your outer pads you probably have something wrong. BMW has used sensors in the inner pads since at least the 80’s, and it does give you a good sense of pad life. Both sides of the axle should be wearing the same, and the inner should only be a few millimeters more worn than the outer, so you don’t need sensors on all four wheels.
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02-23-2021, 10:03 PM	#9
Billfitz Lieutenant General 8221 Rep 16,054 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	On the other hand...https://f30.bimmerpost.com/forums/sh....php?t=1471617
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