[Ducati] Front brake lock-up

[Barry]

Hey Chris

I have had the exact problem with my 748 front brakes, so bad I was 
almost high sided while racing.
Have you adjusted the screw on your front brake master cylinder? 
There is a certain amount of play that must be allowed for the 
pistons to retract slightly into the calipers. If not brake fluid 
could be too full, or air could of got into the system.

I would bleed the front brakes with DOT 4 brake fluid, or if you want 
a better quality brake fluid use Motul RBS600. Air in the system will 
cause your problem. Also little pieces of dirt could be in the lines 
or calipers causing some blockage.  In this case I would get a  big 
syringe and hook up a piece of bleed hose to the calipers and suck 
out any left over fluid and possible dirt. After you have done this 
you can top up the brake fluid reservoir and begin bleeding the 
brakes, make sure and do each caliper, and don't let the fluid get 
below the minimum line mark on the reservoir or air will get into the 
lines. Keep bleeding until there is no air bubbles in the system.

  Take the bike for a ride and use the brakes gradually more and more. 
Then put the front of the bike on a stand when you get home and see 
how much brake drag you have by spinning the tire. Most bikes will 
have some brake drag. The odd ones spin with hardly any drag at all. 
So if you spin the tire and you get 1.5 to 2 rotations, that is what 
I have had on my 748 when it has been working fine, and from all the 
help I have had with my situation I was told that is the norm. If it 
is better than that great.

If you still have a problem, it could be bad O Rings in the calipers 
which would require a rebuild kit, or it could be a bad master 
cylinder. Try  cleaning out the system and re bleeding first.

Barry