Hello all, I've pulled the front rotors on my 308, and the calipers had been sticking for some time before I bought the car. The rotors would have been 22mm thick new, and have a minimum spec of 20mm. At the moment, the wear is down to 21mm. There is a noticeable 1mm lip on the outside. 12k miles on the odometer. This is a very basic question I know, but I'm a complete novice when it comes to brakes... am I better off to have them resurfaced now to remove the lip, or just leave them be and put new pads on? Any advice or opinions greatly appreciated. Many thanks. Image Unavailable, Please Login
I would check them for cracks, severe corrosion and alignment; if ok, then have them re-conditioned and made ready for another batch of miles. Rgrds Peter
I don't like turning rotors because they usually take to much off. If they are crack free and not warped I would use them as is. If you know a good parts place that resurfaces rotors you could ask them to "just take off the lip" and check for flatness.
to have used 50% of wear limit in a 308 in 12K miles is excessive in my opinion AND experience the lip issue is-in practical reality-extraneous to brake function/efficiency. a proper lathe pass will be mid point of hi and low with each successive pass not to exceed .005 per side intil a finish .002/side passs is done...minimum thickness AFTER LATHE WORK-not to exceed 1MM above minimum...otherwise just replace them BALO is the vendor then and now, and they are not toooo expensive, but why throw money away, lathe first, re-evaluate.... the pedal quality will be noticeable even prior to fully bedded in pads...
The only reason to take the lip off in my opinion would be to facilitate pad removal as it can get awkward, particularly with some kinds of e-brake systems, with too much lip on there. If that's not a concern for you (i.e. if you know how to get over that hump) then I'd recommend you just keep on truckin'
Thanks everyone for the replies. Going to keep the discs as is. Yes, the calipers were stuck badly, to the point the heat had caused the wheel bearing grease to liquify and run out somewhat. I have no idea how the PO didn't notice... I had to just separate the caliper halves in-place, since the pistons were stuck so badly, even if I had loosened the caliper from the hub I think the pads would've been a pain to get over the lip (especially while trying to keep track of caliper shims). I don't anticipate this being a problem in the future, though.
As an example, I got 30K total miles and 30 track days (about 3K miles) on a single set of rotors on my F355 (6 sets of brake pads.)