Hi folks, I went to take the bike out this last weekend and found I had no front brake. There is no sign of any leak and the fluid reservoir is at the correct level. I've pumped the lever to get some pressure and tied the lever to the bar overnight to see if it was trapped air, but still no luck. This leaves me thinking its the master cylinder thats gone. Strange as it was working perfectly when I put it away last? Or could it be something else? I don't want to ride to a garage with only the rear brake so I was trying to find a "how to" somewhere on replacing it myself. Does anyone know of one somewhere and how difficult it might be for a novice like myself? Thanks!
Fitting a master cylinder is a piece of cake as there's not really much to it, even less work if the lever is attached to the new one you buy. If not then get the levers swapped over first. Then get rid of as much fluid out of the system as you can before you start. I normally suck up the fluid in the reservoir using a syringe and then open the bleed screws on the calipers and pump the rest out. Then loosen up your brake line bolt, undo the bracket attaching the master cylinder to your clip-on, remove the old part and then bolt on the new m/c, re-attach your brake line making sure you use new copper washers and make sure it's all nice and tight, top up with fluid and bleed it to make sure you get rid of all the trapped air. Hey presto job done.
Take the cap off and you'll see a small hex headed screw. That's the bleed screw for the cylinder. Loosen it a half turn, pull the lever and lock it off then release the lever. Do it a couple of times and the lever should come back. If not, then it's replacement time
Thanks very much for all of that, I'll give Nelly's suggestion a shot and if not then I might be needing that cylinder Nelson. Thanks for the fitting instructions Matt!
Looks like I'll be needing that Nelson, tried loosening the screw and the head snapped off :coldsweat:
Just thought I'd close this thread with an outcome. I tried to carry out Nelly's instructions and unfortunately snapped the head off the bleed screw for the master cylinder. I then received the master cylinder from Nelson (thanks!) and amazingly and thanks to Matt managed to change the master cylinder. Having done so, I then tried bleeding and repressurising the system according to the instructions from Matt and the Youtube video he supplied. It didn't go quite to plan as the brake lever would still not get upto the pressure I needed. I then reverted to Nelly's instruction and tried loosening off the bleed screw for the master cylinder (as described above) and everything came back to life. Which makes me think, if I didn't snap the head off the screw, maybe I didn't need a new master cylinder at all! I'll post what Matt sent me, and the youtube link, incase anyone has similar issues. Quite impressed with myself for managing to do my first job on my bike though. Thanks to everyone that helped and long may it continue to save me expensive garage bills! This is the kit I bought: One Man Motorcycle Bleed Kit, Syringes, PVC Tubing & Motul Brake fluid DOT 3/4 | eBay This is Matts advice: "Right, this kit would be fine yes. Although I wouldn't actually use it the way they've described. I would use the syringe to extract as much fluid as I can so that you can change the M/C without getting fluid everywhere. Once you've got the new M/C on you don't need the syringe's, I'd just do a standard gravity fed bleed, i.e. you squeeze the lever and bleed it out of the caliper. But if you're happy to do it the reverse way then go for it! Essentially all you need to bleed brakes is a tube that fits over the bleed nipple and an 8mm spanner. The syringe is just useful for getting the fluid out. This is a very good video showing you how to bleed the brakes..."
Glad you got it all sorted As you've found out, this video misses out the fact that on a radial master cylinder you have to bleed it at the cylinder as well as the calipers. As for the old master cylinder, you could always get a new bleed nipple - providing you can get the old one out - put it back on and then see whether or not it needed replacing. If it's ok you could either sell it on or I guess, keep it as a spare.
As Ducati don't sell seal kits due to indemnity issues, a spare master cylinder may be a good idea if you can get the broken nipple out.
