I have Cooper S 2009. Do I have to replace the sensor once I replace the front brakes? How do I know if I need to replace just the pads or the rotor as well? (In Mini dealer they told me that I need to replace both pads and rotors)
If the brake light didn't go on, and you can get the old sensor off the old pads and onto the new pads without it falling apart, you can reuse it. If not, it's not expensive anyway. If you have enough thickness to the brake rotors (check with a micrometer that they're less than halfway from new spec 22 mm to the wear limit 20.4 mm) and they're not badly grooved, you can get by with a second set of pads on a rotor. MINI service replaces the rotor every pad change, but if you have a reasonably smooth rotor about 21.6 mm or thicker, you can do another set on the same rotor. The rear discs are 10 mm new, 8.4 mm wear limit.
You can (and should) take the rotors to an auto parts store that has a lathe to turn them (O'reilly does). They will either turn them down to give them a fresh, flat surface for your new pads, or they'll tell you they are too worn to do this. In that case, buy new rotors also.
Or you could go old school and cut the sensor off and and splice the wire together. The light will NEVER come on again since the circuit is completed. Then check you pads and rotors like our fathers did without stupid dash lights. You can see the thickness of your pads with a flashlight so it's easy to eyeball inspect them. As for rotors I replace them with every pad change because the centric rotors (made by Stoptech) are very good and cheap. Brakes are not something to ever cut corners on to save time or money.
I'm not a fan of turning rotors. Removing mass from them makes them nice, smooth & likely to warp. I'm pretty sure MINI dealers changes rotors every time they do a brake job, whether they are needed or not. I look at them check thickness & replace as needed on my cars. For me it is usually 2 sets of pads to one set of rotors.
I've personally turned several sets of MINI rotors, driven harder than most, and had NO issues. 160k miles and counting. But YMMV.
Your all a bunch of old farts! Most parts stores don't know what turning a rotor is. I could only find one guy to turn my brake drums for my old Indian. Times they are a changing
I smoothed down the grooves and removed the lip on my front rotors by turning them by hand while still attached to the MINI and applying a file by hand to each side. Amazingly, it did a nice even job with no runout or vibration and I still had adequate disc thickness afterwards.
Didn't mean to imply I had 160k miles on one set of rotors. Meant that I've been through several sets in 160k miles- probably 4-5, because I keep changing setups. And I turn rotors every time I make a change- probably 6 times on this car, and 6 times on others. And zero potato chip or cracking issues. Just stay above min thickness spec. Orrrr buy new rotors every time, if you like. But my experience would suggest it isn't necessary in every case. Different pad compounds and different rotor materials wear at different relative rates. Some setups will wear out together. Others won't. Especially if you use different pad compounds for different conditions (DD, track, autocross, mountains)
This is a timely thread. I'm about to replace the rear pads and sensor on mine. Just got the package today. About $75 from Way Motor Works. I had been planning on doing all four brakes and rotors with an upgrade from stock, but something came up so now it's just the OEM pads to keep me going for a few months. Stoopid other things that need money.
Sorry I forgot to include this :wink: in my 160K comment. A lot depends on what pads you use as to how long the rotors will last & of course ones driving style. Some aggressive pads love to eat rotors. While some pads are rotor friendly. I think the OP is looking for info for his street driven car. Once you hit the track a different setup from street is the way to go. You can turn yours & I'll replace mine when needed. Different strokes as the song says.
I just got done replacing my pads and rotors BEFORE the sensor lit but now I can't seem to reset the counter. I wait till the reset lights up, then the clock and it goes back to 1000 miles. What am I doing wrong?
Sorry, I don't know what counter are you trying to reset? I don't think there is one associated with the brakes, just a light activated by the wear sensors.
The service reminder on the rev counter that shows date and miles till the next service is due. It shows 1000 miles every time I start the car.
I disable or reset all the crap on my 05. I know when my car needs service better than the dealership of a silly counter. :lol:
I like to wait till I hear a grinding noise, this way I know I have got all the use out of my pads. If wou drive a few days more the metal on metal will mechine the rotors flat.