Rear brake pad light came on for the 2nd time

backslashv · 10-31-2021, 01:58 PM

Hi,

An OBD diagnostic reveled that the cause for the dash light is the wear on the rear pads. The 1st time this light came on a few months ago, I ran the diagnostic and it said the same thing. I opened the wheel and looked at the pad, and there was a lot left. So, I cleared the error and the light went off. A few days ago and after driving ~800 miles the light came on again. I thought now's the time to replace the pads. I opened the wheel again and there is still a lot of pad left ~5mm. You can see the

View post on imgur.com

. The light isn't turning off this time after cleaning the error.
Two questions:
1) Why is the car warning me this early?
2) Do I really have a 2-stage wear sensor? Is it a thing?

4_ring_circus · 11-01-2021, 07:13 AM

Have a look at the pad that is on the inside. The inner pad always wears faster since that is the side that the piston is on. The other issue could be the sliders sticking causing the inner pad to wear down faster.

backslashv · 11-07-2021, 07:20 PM

Quote:

Originally Posted by 4_ring_circus

Have a look at the pad that is on the inside. The inner pad always wears faster since that is the side that the piston is on. The other issue could be the sliders sticking causing the inner pad to wear down faster.

Thank you for your suggestion. The inner one is indeed thinner, but it still has about 4mm of pad left. Don't you think? Is the slider the part that houses the pads? If yes, it came off without much force.

View post on imgur.com

4_ring_circus · 11-08-2021, 06:48 AM

I circled the slider in your pic (sorry for using your image). These should slide in and out with a little resistance, it should just be the rubber boot holding them from sliding. On all my cars I clean and re-lube the sliders every time I have the caliper off.

10-31-2021, 01:58 PM	#1
backslashv Second Lieutenant 106 Rep 247 Posts Drives: 2022 BMW M3 Competition Join Date: Apr 2015 Location: California iTrader: (0)	Rear brake pad light came on for the 2nd time Hi, An OBD diagnostic reveled that the cause for the dash light is the wear on the rear pads. The 1st time this light came on a few months ago, I ran the diagnostic and it said the same thing. I opened the wheel and looked at the pad, and there was a lot left. So, I cleared the error and the light went off. A few days ago and after driving ~800 miles the light came on again. I thought now's the time to replace the pads. I opened the wheel again and there is still a lot of pad left ~5mm. You can see the View post on imgur.com . The light isn't turning off this time after cleaning the error. Two questions: 1) Why is the car warning me this early? 2) Do I really have a 2-stage wear sensor? Is it a thing?
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11-01-2021, 07:13 AM	#2
4_ring_circus Private 14 Rep 71 Posts Drives: Corrado, Audi S4, X1 128xi Join Date: Apr 2019 Location: London, ON iTrader: (0)	Have a look at the pad that is on the inside. The inner pad always wears faster since that is the side that the piston is on. The other issue could be the sliders sticking causing the inner pad to wear down faster.
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11-08-2021, 06:48 AM	#4
4_ring_circus Private 14 Rep 71 Posts Drives: Corrado, Audi S4, X1 128xi Join Date: Apr 2019 Location: London, ON iTrader: (0)	I circled the slider in your pic (sorry for using your image). These should slide in and out with a little resistance, it should just be the rubber boot holding them from sliding. On all my cars I clean and re-lube the sliders every time I have the caliper off.
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