Wear indicator on rear brake pad question

[paulo57509]

Maybe the justification for just one screech spring relates to electrical wear sensors. The LS has only one electrical (sacrificial) wear sensor for the front and rear. If it's good enough for an electrical sensor, it's good enough for mechanical ones.

The world may never know.

 

[Opelman]

A pad wear sensor is not new tech. I had a 2007 Golf that had them.

Early 80s Peugeot 505 had electronic pad wear sensors. Super simple, copper piece inside the brake pad at the wear limit would ground against the rotor and illuminate a light on the dash when exposed by wear.

 

[kschachn]

Early 80s Peugeot 505 had electronic pad wear sensors. Super simple, copper piece inside the brake pad at the wear limit would ground against the rotor and illuminate a light on the dash when exposed by wear.

Yeah the ones on my BMW were similar except that it was a simple wire embedded in a plastic holder. Once the wire was worn through and the circuit broken it illuminated a warning on the instrument panel.

 

[Elkins45]

Twice in my life I have let my brake pads get worn down to like 1-2mm thickness. Both were the factory pads, my dad’s 98 Chevy on the front and my 2016 Mazda on the rear. I never heard the squealers, but I wasn’t listening for them because I wasn’t expecting the pads to be worn down so soon. In the case of the Mazda I had the windows down pulling up to a gate and I heard the rivets grinding.

Maybe my high frequency hearing is shot? In any case the squealers don’t seem to be much help for me.

 

[John105]

Early 80s Peugeot 505 had electronic pad wear sensors. Super simple, copper piece inside the brake pad at the wear limit would ground against the rotor and illuminate a light on the dash when exposed by wear.

This illustrates the different business model with German and Japanese.

OE brake sensor wire, 2021 7 series, $41.

34356890791 - 2016-2023 BMW Wear Indicator (34-35-6-890-791) | BMW of South Atlanta Parts

Wear Indicator for 2016-2023 BMW, Part Number 34-35-6-890-791.

parts.bmwofsouthatlanta.com

2021 LS, $135.

Lexus LS 500 Disc Brake Pad Wear Sensor (Right, Front) - 4777050120 | Prestige Lexus, Ramsey NJ

Disc Brake Pad Wear Sensor (Right, Front). Brakes, Suspension. Lexus LS 500. Genuine Lexus Part - 4777050120 (47770-50120). Ships from Prestige Lexus, Ramsey NJ

parts.prestigelexus.com

With Germans there is so much OEM, that going OEM over OE, often the part is $12-$15. Identical part, no blue BMW box or bag.

With Japanese there is “word of mouth” OEM such as a Koyo idler etc, but it’s so obscure that in reality there is OE or aftermarket. Sometimes, no aftermarket. My .02 from getting a Japanese car in 2016

 

[Popsy]

I'm pretty sure the wear indicator that @Jeep_Riot is referring to, is just the screecher stick, not an electronic wear sensor.

His car is a '15 Crosstrek, not an Audi or such.

I had the electronic wear indicator on my 98 Fiat
And a lightbulb monitoring system too...and a fantastic automatic AC. I miss that car.

That said, maybe it's weight related, but I've often noticed on people's car where I changed brake pads (never on my own car, but I do tend to change early), the (front) driver side was always a bit more worn than the passenger side. Always puzzled me.