Ok, I put a brand new wheel on this week. I didn't have to dissassble the front calipur or mess with the brakes in any way. Now when I roll the bike ten feet back or forward the front brake has nothing. I pump it up and they work, let off and after another ten feet of rolling there is not brake again. I have blead the system. There is NO air in it yet it sure acts like it. I have brand new pads so I know that is not the issue. There is no leak at all anywhere in the system. I have blead the whole system from the bleeder on the calipur and all so with the master cylinder cover off I have gently pulled the brake lever and watched for air bubbles. NONE. If I pump the handle up and walk away for an hour or more, it stays hard and up. Move the bike ten or twenty feet and nothing, the handle pulls to the throttle and nothing there. When looking at it with the master cylinder cover off and depressing the lever fluid rises up in the master but no air bubbles.

The only think I changed was the front wheel, absolutely did NOT touch the brake system. Old style banana calipur on the front but no cuts or leaks in the rubber or anywhere in the whole system.

Any ideas

randy
1974 FLH

 

If it didn't squirt you in the eye when you applied the brake with the MC cover off....It is Not Bled.

Is this on an FL? I never have replaced a Wheel without removing the Caliper.

 

Yes I does squirt up inside the master cylinder with the cover off. Doesn't make any sence at all. I have no leaks anywhere. I have no bubbles out the bleeder or in the master. I can pump it up and its hard as rock and will stay that way. but roll the bike twenty feet and I have no handle at all. Pump it up and the brakes work. Im going to try something. I going to heat the calipur with a small ceramic heater. Perhaps if there is some fluid movement inside the calipur due to convection currents caused by the heat, perhaps if there is air bubbles they will move. Not hot enough to hurt the rubber but enough to get the fluid hot.

randy

 

OK...Get a piece of paper...after you roll the bike see if it will slip in between one or the other side of the Brake pads to rotor...I'm Thinking you have a very bent rotor...spreading the pads excessively.....

 

Nope, not warped. I know how a warped rotor feels like and this is definitely straight.

randy

 

Is it the same rotor that was on the old wheel before the change or a new rotor? and if new is it the same thickness as the old?

 

Oh...Forgot that one...had it before. Thinner rotor=bad ju-ju
Sometimes by compressing the caliper at least halfway...[not too far cause yer gonna loose Fluid from a too full MC], Then Use the lever to bring it back out...it may just get it's **** together...mine did Not. Needed a thicker rotor.

 

Yes the same rotor and it mic's out at .25 inch thick.

randy

 

Rotor the same, caliper is the same, new brake pads sure sounds to me like you have air trapped in the line somewhere, I know you said you bled the system but by your description there is air in the line, the fact that you can as you say, "Pump them up", tells me that there is still air in them.

 

Sounds like you still have air in the line. Pull the caliper bolts off and rotate the caliper so the brake line is sitting at 12 oclock, straight up. Now follow the brake line all the way up to the MC and make sure it is all vertical. You want the air bubbles to travel upwards. You might want to disconnect the two hydraulic line brackets on the fender and forks.

Take off the mc cover and make sure that the holes in the bottom of the fluid resivoir are open. a little tiny drill pushed through will tell.

Now work the lever a little. Pull it back slowly all the way and let it snap back. Wait a little bit then open it slightly and watch for bubbles. Tap on the brake line at the mc gently with a hammer handle. Keep working the lever looking for bubbles and tapping the line just outside the mc. That should get everything out.

When you think you have it all, let it sit over night and crack the lever in the morning and hold it that way. You might have a few more.

This method takes a little while but has worked well for me.

carl