sleeperwagon

My g/f went took the car to some random tire repair shop today (slow leak). The mechanic told her that there was only 1mm left on one of the front pad (don't think he checked the other..). So i have two questions for you guys:
- shouldn't the brake pad wear light be turned on?
- does this sensor often screw up and not light up the brake wear light (is it a common problem?)
- how bad is it to drive around with 1mm left? I'm thinking that I've been driving 50k with 11mm, so 1/11 should last a couple thousand miles...no?

Looking forward to hearing what you guys have to say about this one

Cheers

vkhong

The pad wear sensor comes on at 3 mm. So one has 8 mm of useful life. I would not recommend using pads of 2 mm or less. When I installed BMW pads and BMW sensors, the computer reset gave me 32,000 miles for the rear and 29,000 miles for the front. So approximately 3750 miles per mm. This is only an estimate, since pads can wear quickly with more aggressive driving or on track days. Once the pad sensor makes contact with the disc, you may also notice that the mileage countdown becomes proportionately quicker. Your mileage may very depending on type of brake pads, rotors and driving patterns. At 1 mm, your brake calipers and fluid also runs hotter than with 3 or 4 mm of pad.

Lotus99

Why risk anything to do with brakes just to avoid having to spend a few hundred bucks that you'd have to spend a few months down the road anyway? So it's not a real cost savings if you do it a bit earlier, but a big piece of mind. Seems very low to me.

yeewiz

to answer the original questions:

1) I think so, but the mechanic probably meant you had 1mm to the sensor
2) No
3) To be safe, you should take time to take the tire off and check yourself just to be sure. I'll guess the sensor wire is on left side (E61 experts correct me, but I just did my E34 and it was left). Follow the wire to the disk pad and see if the plastic sensor at the end of the wire is touching the rotor or if the wire is flapping in the air cuz you've burned through the sensor. Unless the rotor are actually touching the pad backs, you probably have time to buy new pads and install them.

sleeperwagon

Thanks for all the answers. Very appreciated. I ordered front/rear zimmerman rotors and Hawk HPS pads...now I need to get my hands on a service manual to do a nice diy job