2000 Ducati 748 Brembo MC and calipers Notably, I have no idea what I'm doing, ever. I just guess, and so far, so good, until today. I removed my front calipers to clean them. Brake fluid drained, and pistons removed. Upon reassembly, I pushed the pistons all the way into the calipers, reassembled the latter, then put them back on the bike. Fluid was filled, and then I pumped the lever. Nothing. Not to worry, I've never bled the brakes, and this seems like a good time to learn. I figured that when the fluid drained, air replaced it inside of my steel braided lines, so I needed to bleed it out. It seemed logical that I should open the valve, depress the lever, then close the valve to get the air out. Eventually, it worked with brake fluid escaping through the valve. So now I believe I have the calipers filled with juice, and some of the pistons have extended partially. However, I still have no feeling in the lever, and I can't get the pistons to move out far enough to put the pads on the rotors. Suggestions? P.S. - Is brake fluid slickery like anti-freeze? Some of it spilled onto me tyres.
That series of actions will continually let air into the system... Fill the reservoir with fluid, then depress the lever before you open the valve to build pressure, then while still depressing the lever, open the valve a bit and you will feel the lever move in. Close the valve before releasing the lever again. Add more fluid into the reservoir as needed... Continue until all of the air is out of the system and the lever pressure is firm. You may want to use the search function for complete instructions...
I feel no pressure in the lever at all. It's as if there is a leak somewhere, but I'm pretty darn sure there isn't.
You've got a lot more work to do in bleading the breaks before you get pressure. When the first fluid starts comming out that is only the start of the bleeding process, you could still have tons of air in the system. You'll need a speed bleeder on the end if you want it to be efficient, but you can get by without it. To start off with, have the resevoir top open. Then you'll have to pump and pump and pump and pump and pump for a while (could be a hundred + times easy) to start building some pressure. Then hold the lever down and keep it drepressed. With it depressed, open the valve and start letting some fluid + air bubles squirt out, and then tighten it back down, all without ever letting the brake lever out any. When the valve is closed you can let the brake lever out. You may have to do this 4 or 5 times or more on both sides before all the air bubles get out. You should feel the pressure get more and more with each bleed session. You should really read up on this to make sure you get it right, its a pretty important part of the bike and you don't want want to lose pressure when you really need it.
Here's a few helpfull hints when bleeding from "scratch". Open the bleeder screw and pull the lever in as quickly as possible one time. Close the bleeder and SLOWLY release the lever. (The lever "chop" method pushes air much better than trying to compress the air with multiple "pumps" IMHO.) Wait a few seconds and rapidly "twiddle" the lever in and out a few millimeters a dozen or so times to "milk" some of the micro-bubbles out of the M/C's bore. However you (lever) bleed the system, always release the lever slowly and allow a few seconds between bleeding "cycles" to allow the fluid to fill the M/C bore.
awesome, I've got some pressure now. I was pumping for three hours!!! I still don't have 100% the feel as I did before, but I think some running up and down the block will jostle the rest of the bubbles out. I noticed that if I fiddled with the lines, more bubbles came out, so hopefully that L-Twin rumbling about added to some bumpy pavement will work the rest out. Until then, I pushed the lever out as far as it will go. I'll put it back when it gets really tight. Hopefully I don't die in the process lol
You don't ned to ride to get it done. When you have good pressure at the lever you can tie it pulled and leave it there for a couple of hours. Then go back through the bleed process...m/c, one caliper, the other caliper, back to the starting caliper and finally the m/c.
Kendrick, bring it to my house and I'll do it and show you how to do it for next time. Riding it with spongey brakes is asking for trouble.
The pressure is 100% now! That was one heck of a long process. I had the brakes torn down, cleaned, and reassembled in under an hour, but the pumping took up so long I think I need to get a speed bleeder at the very least. A friend told me about a syringe tactic that I might try out. Anyone done that?
If it took three hours you were definitely doing something wrong. It usually takes about 10 minutes or so.
