Front brakes are locking up.

[fauxamish]

As stated, my front brakes keep locking up. I did the 450r conversion and now about 20 minutes into a ride, they lock up and the front wheels will not turn. I greased the slides and changed rotors, and it was good the last 2 short rides I did, but today it locked up again. Any ideas?

[quad2xtreme]

When they have locked up, how long does it take them to unlock? Do they ever release?

Once locked, I would open the bleeder valve to see if that suddenly frees up the pressure.

[fauxamish]

Yeah, they release after about 15-20 minutes. The lever cannot be pulled in when they are hot. I figure it must be a little water in the fluid...

[quad2xtreme]

Originally posted by fauxamish
Yeah, they release after about 15-20 minutes. The lever cannot be pulled in when they are hot. I figure it must be a little water in the fluid...

not sure that would cause it.

Sounds like a bad master cylinder or calipers need a rebuild or replaced.

[fauxamish]

What could it be in the master? I do not think that the piston in the cylinder is sticking. Anything that you can think of that I can try before replacing?

[quad2xtreme]

it is a strange problem...usually you don't get enough pressure.

If it sticks and both are stuck then somehow it isn't releasing the pressure which would point to the master cylinder. Otherwise, at least one of the calipers should let the wheel spin freely.

[quadrider00]

check the pressure relief port in the brake resivoir it may b clogged up

[fauxamish]

Ok, that is the other hole in the master cylinder? Because my clymer manual for the 400ex shows one hole and it was clean in the 450r master cylinder, but there was another that I didn't know about... I will try that. Thanks.