Brake Pistons not fully retracting

[collins_dan]

Just replaced the seals on front and rear brakes. Everything went fine, used lots of rud rubber grease..., but front pistons are not fully retracting, so pads are lightly touching the rotors. I'm thinking that I should just go through a couple rounds of pushing pistons fully home and applying brakes. Other suggestions? Thanks, Dan

[Galwaylotus]

Careful!!! I had a sticking pad - not piston but a similar effect. I wound up frying the caliper and pads on that corner and boiling the brake fluid in the process. That left stopping quite exciting!!

[AHM]

Have you driven the car or just spun the wheel by hand? What are the symptoms?

There is no retraction mechanism and they should not fully retract. There may be some very light contact but after one revolution they shouldn't "Drag"

[collins_dan]

I haven't driven, just spinning wheels by hand. The contact is very light. All wheels still spin a couple of revolutions. The back seems to spin more freely than before, front spun more freely before. Maybe a full revolution or 2 now, whereas before it seems like 3-4. Thanks, Dan

[Galwaylotus]

That doesn't seem like a problem to me. Disc brake pads run very close to the disc and what you are describing sounds as though there is no drag worthy of concern. Try a coast-down and see if you notice any drag.

[collins_dan]

Will do. I didn't seem like a huge worry to me, but I could hear the pads touching the rotor now, whereas I couldn't before the rebuild. Thanks, Dan

[robertverhey]

Did you skim the discs? Thinking it might just be the high points making contact until the pads bed in (and conform to the profile of the disc face)

Robert

[RedS4]

I have developed a problem which I believe to be a dragging brake - after a smalling trip the LR wheel is covered in brake dust and the wheel is quite warm. The pedal feel is quite good (not hard and with just the right travel).

Does this sound like a sticking piston - or at least a piston that doesn't retract properly? It's not the handbrake as it needs to be adjusted up (it doesn't make contact right now....).