Been a while since I was on here. Last week was on the xway at about 80mph, smelled something and noticed I was braking without touching the front brake. Got it off to the side and the front brakes locked up. Loosened the right bleeder and got home using the rear brake. Burned up my mirrored rotors!
Got new rotors, pads, 2 caliper kits and a master cylinder kit. Pulled and broke open the calipers, removed the pucks with compressed air. Cleaned everything, installed new seals. Pucks were fine, some morsture behind them.

Cleaned and rebuilt master cylinder with new piston, spring and seals.

Installed all and bled brakes with mityvac. got about a 1/2 cup of water/morsture out the bleeder. Pumped full can of brake fluid thru the system to replace all fluids.

Took it on a 2 mile ride, did the same thing. Disassembles and re-assembled everything. Another ride, same thing.

2006 Ultra Classic

Sorry about the long post but any ideas would be appriciated.

 

maybe your brake lines are collapsed or collapsing letting the fluid down to the caliper but not letting it back to the master. try getting the brakes to lock up then take the banjo bolt on the master loose and see it they release. if not then go down to the caliper and do the same there. if that solves it go sponge for some nice braided lines.

 

I'll give it a try but already have braded lines. Do they go bad also?

 

uhh i didnt think that they would. I think that they are built with a poly tube with the braided line on the outside to keep it from bursting. id still give it a try tho

 

Something is keeping the fluid from retracting back into the reservoir. I am sure you greased the brake pad pin to help with retraction. Make sure that you have everything where it is supposed to be in the calipers and in the MC plunger. Don't overfill the reservoir. Use the correct DOT rated brake fluid. Probably DOT3 or 4.

 

I didn't the grease the pins but I'll give that a try. When they lock, I can open the bleeder a bit, release some fluid and the brake release. Makes me think it's not the pads sticking. I've got the master off again now. Hold my finger over the banjo hole and I get pressure, release and I get suction enough to pop when I remove my finger. I guess it's working correctly.

 

Are you sure the MC is ok? Sounds a lot like the problem I had years ago which turned out to be the MC.

 

If both side are locking up on you I would suspect that there is something up with the master cylinder.

 

I'm guessing the same thing. Just can't imagine what it could be after replacing all the componets.

 

Had happened on wife's 08 UC after completely rebuilding the MC it disappeared.