I just replaced the front brake caliper piston seals and dust boots on my 240. I also replaced the "warped" old rotors. Yeesh! 10 pistons and 8 bleeders... that was fun. None of the pistons had anything more than a half-ring of surface rust, which came off (all but 1) with a rag and brake fluid. The other got some very fine sandpaper.

Anyway, I had a hell of a time bleeding from all those ports, but I finally got it done. I bled from the bleeders in this sequence: Circuit A: Rear passenger's, Front passenger's lowers (outside, then inside), Front driver's lowers (outside, then inside). Circuit B: Rear driver's, Front passenger's upper, Front driver's upper. The front lower inside bleeders were stiff to open and to close. The outside passenger's seems to be weeping a little around the threads after test driving.

I got air into the MC at some point, and wound up bleeding 3 times. At the end of it all, I had a nice firm pedal with the car off. With the car running, the pedal has free travel, then becomes firm and responsive. I drove the car to bed in the rotors, and the pedal became more and more responsive as time went on. Or maybe I just started to drive like normal and stop over-analyzing the pedal feel.

As for the slight leak at the bleeder... Does that spell a replacement caliper? I really hope not. I could probably tighten the bleeder more, but it seems like it's already plenty tight.

Happy Bricking!
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740T and 244DL - Frank the Tank @287K mi. and The Polished Turd @237K mi.