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Sometimes I pull in my front brake and the lever barely moves before braking and sometimes the lever moves like half way before braking. I bled the lines last weekend so I either didn't get all the air out or its something else.
I normally notice that situation where the lever barely has any "play" is when the bike is ridden for the first time in a while. One time I could tell the brakes were being applied without my doing so and I had to push the lever out so I wouldn't be "riding" the brakes.
Thanks for your input.
-Andrew

Andrew,

You still have air in the lines. Do not ride the bike until you do a proper brake fluid bleed.

It would help us if you describe how you bled the brake lines. Something in your procedure allowed air into the lines.

Do not ride the bike until this is resolved.

Andrew,

You didn't state if you have ABS brakes, however, the one where "you had to push the lever out" is not in line with a properly operating system.
Something is hanging up that prevents the Master cylinder piston to return to it's "home" position.

If you have ABS, then things get complicated....in any event I don't think is safe to operate the bike if you have a questionable brake system.

I used the mitivac method where i hooked it up to the nipple on each caliper and sucked the fluid thru until it came out clear. while there was pressure, i would tighten the nipple back up and then remove the hose to the mityvac. I used new BMW dot 4 fluid.
No ABS.

I wonder if I should have pulled the lever a few times while draining/refilling the resevoir (yes I did check the resevoir and made sure I didn't get too low before refilling to the top) I could see the tiny hole at the bottom of the resevoir where the fuid goes to.

It could be that little wheel on the lever for the reach adjustment..I think it has 3 or 4 setings..normally you push the lever away and turn the wheel.

Maybe with gloves you are turning it accidently...just a thought..I sometimes find that mine has moved.

DJ

Andrew,

Since brake fluid is inexpensive, you may want to try another brake bleed following Dallara's method (below). Dallara used to be a great contributor to this board but has moved on. His mechanical advice was always accurate and very thorough.

I have ABS so I leave the brake bleeding to the BMW mechanic. With ABS, it's a bit more complicated with an additional circuit that needs to be bled, located under the tank.

Dallara's Brake Bleed Instructions:

1.) First of all, rubber band or tape a thin piece of wood, etc. to the throttle grip. Quarter to a half inch thick should be fine. Why? Because you can actually pull the lever TOO far back, which pushes the master cylinder piston too far and allows air into the system from the back of the piston. After you have done front brakes a bunch you learn to use your ring and little finger as the *spacer* to prevent this from happening, but when you're starting out the piece rubber-banded to the bar really helps. I still have the strip of wood I learned with in the top of my toolbox from over thirty years ago...

2.) Cinch the bleeder down on the caliper. Forget the Mity-Vac for a minute. Pump up some pressure by pumping the brake lever in and out vigorously for about a half dozen cycles. Now hold the lever against the *spacer* you have on the grip, grab a wrench and JUST *crack* the banjo bolt where the brake hose connects to the master cylinder. Remember, air rises in the system (and we'll come back to this in a moment...), and quite often it is trapped in various places where the system makes twists and turns. We want to work from the top to the bottom to try and eliminate any of this higher-up trapped air. Make sure you have a rag handy to wipe away any brake fluid that leaks out around the banjo fitting. Once you have just cracked the banjo bolt look to see if any air bubbles come out. If so you will have to repeat this procedure at this fitting until you get nothing but fluid. You have to be quick. Just crack it as you maintain pressure and then cinch it back down again... It all happens in about a second if you have it right, and it is all a smooth, controlled series of actions. Pump the lever. Get your wrench ready on the banjo bolt as you hold the brake lever just slightly in. As you pull the lever back toward the grip crack the banjo bolt and watch for bubbles, then as the lever nears the grip cinch the banjo bolt back down. Wipe away fluid. Repeat until there is no air.

3.) Go anywhere along the brake line and repeat this same procedure above at each banjo bolt fitting, including the one on the caliper. Also, just before you do this at each banjo bolt tap the brake hose with your wrench... Just lightly. You're trying to make the air get moving toward where you're bleeding so it can get out.

4.) Okay, once you are sure you have cleared any air near the fittings, make sure you have the master cylinder topped off. Now do your manual bleeding at the bleed fitting at the caliper. Again, forget the Mity-Vac for minute... We'll get back to it. See if you get any air. If you do it should be minimal. In fact, I recommend you bleed the brakes completely by hand... No matter how long it takes you or how much brake fluid you go through... Until you can do it blindfolded and get a solid, firm lever and stout brakes... Only then should you ever tackle a Mity-Vac. Why? Because like any other supposed *miracle tool* it is way, waaaaaaaaaay too easy to overdo it.

Mity-Vac's, IMHO, are most useful for changing out fluid, not for bleeding. It's way too easy to suck air in all sorts of places with the tool, but remember one very, very important thing... If you are letting in air at the bleeder fitting valve (i.e. around the threads as you describe) it is most likely staying in the vicinity of the bleeder. It is almost impossible to have it travel from there up the line... that is unless you suck in a LOTof air.

Now, if you want to try and use the Mity-Vac for bleeding, try this... Remember our little piece of wood? Well, make sure you have this rubber-banded or taped to the grip, make sure all the banjo fittings are tight, and most of all - make sure the master cylinder reservoir is FULL. Now, before you ever open a valve or pump the handle on your Mity-Vac... Pump up some pressure in the system by pumping the brake lever in and out several times, then hold it against the grip and rubber band it to the spacer and the grip... Now, lightly pump up some negative pressure in your Mity-Vac, and then crack the bleeder valve. Carefully watch your reservoir level as all too easily you can draw it down to empty. Still, if you just cracked the bleeder valve a tiny bit you can throttle this from there. If you get it right you can watch a steady stream of bake fluid go right through the line, and if you get really, really good with a Mity-Vac (and mind you, I am not nearly this good with one... and I have one of the trick alloy ones with all the bells and whistles... I still prefer to do my brakes the old fashioned way) you can change out the entire front brake system fluid of a single disc bike in no more than three of these cycles.

Now there is another way... If you have the right Mity-Vac. Some Mity-Vac models (and mine is like this) you can switch from pulling a vacuum to pumping pressure. With one of these you can fill a brake system from the BOTTOM chases all the air to the top all along the way. This works best refilling nearly rebuilt brake systems.

Another option you have is removing the entire brake master cylinder, hose, fittings, caliper, etc. and bleeding it one the bench... This way you can make sure the caliper and its bleeder valve is the highest point in the system, and so chase the air to there. Just make sure you have something the approx. width of the disc to put in the caliper between the pads. That's imperative.

Many times, when I ran across a really recalcitrant brake sytem on a customer's bike I often found it an actually time saver to pull the calipers and lines off the bike (leaving the master cylinder on the handlebar) and hanging the calipers up above the master cylinder with a piece of wood in between the pads... and then just bleed them that way.

Hell, at one time we had a vat of brake fluid, and actually assembled entire motocross bike brake systems fully submerged to make absolutely sure we had no air in the system!

Hope some of this helps, and that you will try it out... After that, if you still have a question I'll see if I can help figure it out with ya'!

Cheers!

Allan (Dallara)

Could be the Bobbins are sticking on the floating disk. That would certainly give you the symptons you have.