Brake pressure issues

[thought]

Hey guys,

Trying to figure this out but I cant.  I have a bike here that's using Brembo RCS masters going to monobloc calipers.  A month or so ago it was experiencing weird issues where, while sitting and not riding, the brake lever would come back to the clip ons, but then on the second pump, firm up.  We bled both the lines and the masters and it seemed to get better.  However, now, the lever is firm when the bike is not being ridden but the brake engagement point will change randomly while riding.  It always still works, but it will either work at the 75% mark or the 20% mark now and will generally feel soft.  But once the bike is stopped it seems to be firm again.

Any ideas?  I will try bleeding them again but it could be something else?  Piston getting stuck?  Dirty calipers that need cleaning?  Leaking seal?

Thanks for any help on this

[Howie]

Bleed again, slowly.  Keep the master as close to horizontal as you can.  Tie the lever to the grip overnight.  If you still have a problem you either have a leak or a bypassing seal in the master.

[thought]

Thanks howie... but after some more googling I think it might be a bent rotor. From this link:

http://www.riderforums.com/z1k-z750-maintenance/68857-need-some-help-brakes-lose-pressure-when-rolling-after-recent-service.html

Makes sense because it explains why the pressure is perfect when it's still but weak when it's moving.  What do you guys think?  Gonna have it checked out today... but IIRC the problem started to happen after we changed the front tire on the bike.  Could have gotten banged when it was off for the change.

[Howie]

Do you feel pulsation when braking? 

[thought]

I'm going to double check today if I can get on the bike, but nothing major that I've seen but I havent really looked for it.

But I'll def be bleeding the lines offhand.