I need to wire my brake wear sensor to trick the system into thinking it's OK. Does that involve CLOSING the circuit (connecting the leads?) or opening the circuit (keeping leads apart)? I am assuming it is closed b/c leaving it open did not clear the code.

So, the job is a cinch. I won't describe the brake pad replacement part since it's probably done elsewhere. (And changing pads involves a lot more skill and nuance than the rotors!) Once pads are out, there are two big 18mm bolts that hold the caliper to the hub, on the back of the hub. Box wrench (used 19mm - why don't they seem to make 18mm?) and a rubber mallet to pursuade, and they were off. Caliper off and resting on a box (not hanging by brake lines). The set screw for the rotor is a big torx. I only had a torx screwdriver, but put a big box wrench on the screwdriver handle. Popped loose and unscrewed easy.


Here's the only possible hang-up. One of my rotors was seriously rusted to the hub. Rubber mallet couldn't budge it, nor could hammer blows, wood blocks or a combination. Knowing that the rotor was trash anyway, I took a 25 lb iron dumbell and whacked the rotor near the edge. That did the trick.

New rotor goes on with the set screw (use blue locktite), then the caliper with the two 18mm bolts, then pads, then the wheel. I did a quick cleaning before putting on the wheel using brake cleaning spray. With all the parts and tools readily available, I think I could do a full 2-wheel brake job in 30 minutes. I wonder what a dealer would have charged me. Total cost was about $350 in parts.

Took the car out for a series of 6 or 8 hard stops to heat cycle the pads and transfer pad material to the rotor. So far, not even a squeal. I love the smell of smoking brakes!

So, what do you do with old rotors?

 

I'm pretty sure you break the circuit, since as they wear, they close the circuit. Wear sensors are cheap though, I would just put new ones in.

I still have my old rotors laying around - not sure what to do with them, I guess junk them on one of those neighborhood-pick-up-anything-and-dump-it days.

 

That's what I thought, and I left the wires apart, but the light stayed on. Today I twisted them together, and the light is off. So I guess an OPEN circuit occurs when the wear sensor is tripped. Surprise to me too. I would think it would be easier to close a circuit.

 

Most safety circuits are wired 'normally closed', so that a broken wire indicates unsafe (otherwise a broken wire would render the safety circuit unusable).