Bruce In Philly

2009 C2S 186K miles - REAR brake job

Dash light popped. Ok, so how many miles can I go before I really need to change my brakes? For my fronts, I calculated about 8K miles to be safe. For these rears, let's see:

- Pad plates are about 4.75mm
- New pad friction surface 11.5 mm
- Thinnest pad out of four was about 4mm

I went about 186K miles on these rotors and pads... so you do the math... around 60K miles more... yep you read that right. For the fronts, read my analysis here: https://rennlist.com/forums/997-foru...ter-light.html

Brake sensor myth: The light pops when the sensor line is cut.
Truth: Nope... appears to pop when the circuit is grounded.

On my car, it appears only one sensor actually popped the light and other three had no metal exposed. What really grounded the circuit was the lip on the rotors and not a low pad surface. See below. That shine is the metal appearing. This was the only sensor with metal showing. I suspect this explains why the light will pop on... then not appear again for many miles, then pop on... etc... then pop on with greater frequency until solid.

My rotor wear dimples were virtually gone although I could tell where they were... they were almost erased.

Peace
Bruce in Philly (now Atlanta)

jbkusa

You get incredible life out of your breaks. As for the wear sensor… I disconnected mine when track use was frequent and just unplugging and zip-tied out of the way with no lights.

Bruce In Philly

So you really didn't disconnect, but pulled the sensors out of the pads... correct? If you really disconnected the sensors by pulling the plug from the socket behind the carrier, you should have got an error light... no?

Peace
Bruce in Philly (now in Atlanta)

yvesvidal

He probably installed a jumper, otherwise there would be an alarm.

Yves

bbinder

No. I did the same thing: pulled the sensors from the pads and tied them back. The car thinks that my pads are good forever because the circuit is never closed. I visually check the pads frequently.

workhurts

I think the car thinks the circuit is never open, not never closed. Unless 997.1 and 997.2 cars are different, light stays off with a closed circuit. My guess is the light goes on with increased resistance so either kinda touching a rotor or completely open. I cut, soldered and heat shrunk mine.

scorcherjf

I've been doing this as well for years. Zip tied the sensors away and never had an issue but recently I have a brake pad wear warning popping up intermittently so I assume one of the sensors has corroded over the years and actually tripped? I haven't had time to look at them but is there a better way of not dealing with these sensors other than zip tying them off to the side? My pads have plenty of meat and I swap pads regularly during track season so I'm not worried about the actual brake pads.

Bruce In Philly

Purchase a set of cheapo, aftermarket sensors. Then cut the wire, solder them together, and shrink tube them. What is nice, is that you only need a small "tail" from the electrical plug so no need to tie anything off. You can return the system to normal simply by reinstalling in the original sensors.

Peace
Bruce in Philly (now Atlanta)

scorcherjf

Haha... yes this does seem like the optimum solution but I don't have a soldering iron and the last time I soldered anything was back in high school... I suppose it can be a project to do to pass the winter blues. Just to confirm - the sensor is supposed to be closed to produce no warning light and when the brakes wear down the sensor it opens the circuit and gives you the warning? So soldering the wires together will keep the circuit permanently closed?

jbkusa

What they said... sorry I didn't mean to confuse.

Wayne Smith

I suspect the circuit starts with a resistor to limit current to the wear indicator. As long as the wear indicator connects only back to the sense circuit, then the sense circuit gets a 12 volt return and all is good.

If the pads wear to the point that the sensor connects to the frame (negative) then all current goes to ground and there is no 12 volts returning to the sense circuit so a fault is indicated.

There is no such thing as a good connection. If you have bypassed the wear indicator and are getting failures then unplug and plug in the connector a dozen times to clean the contacts.