Ducati Monster Forum

Long story short, I had someone hit my parked bike and do damage to my rear brake, that I didn't catch until I was in the middle of the street. Rear brake was locked and I "forced" it across the street and onto the sidewalk. Removed the rear caliper and drove it the two blocks home. Over the course of a week I did the minimal repairs to get it going again, but with mushy rear brake, enough to hold me on a hill but not much else. Firday I tried bleeding it, but lost all brakes. I moved out the adjustment bar on the brake lever. I've tried taking the caliper off and moving it to the top of disk. I tiewrapped the lever down overnight and just finished trying the mityvac, but no joy. In all cases minimal fluid comes out of the bleeder. Took the caliper off last night and cleaned it and found that only one piston is movable, the other is fully retracted. My next course is to take the master off and see what's going on under the rubber boot. Monday I'll take the caliper around the corner to a bike shop and see if they can move the pistons with compressed air. Anything else I need to be thinking about? Thanks in advance.

I'm guessing, but believe the master cylinder is probably whacked.

does the piston/rod move or is it bent?

If you mean the adjuster rod on the lever, no it's not bent, but it did go into the master cylinder at a weird angle, before I replace the lever pin, spring, and bent the lever back out a bit.  I'm thinking the master is shot too, cause almost no fluid comes out of the bleeder. When I pulled the caliper off and moved it to the top I hit the lever a couple of times and the pads didn't move at all. No leaks around the pistons on the calipers, so it seems the seals there are good. From looking at the parts catalog, Ducati does sell the internals of that MC, so is there someone else thats sells a rebuild kit or am I left buying the whole MC?

I believe we have a winner...and at 1/3 the ducati price!

http://www.yoyodyneti.com/ProductInfo.aspx?productid=10.4776.51

Also, you generally have to take the rear caliper off, and hold it up well above the master with the bleed screw on top to get a good bleed out of it.

Justin

sounds like you'd need a another few hands to accomplish that

If you want to get by with spending less and doing a little more work, then this could be the ticket. Rebuilt mine with this kit (situation kinda like yours) and the master work perfectly after the rebuild.

http://www.yoyodyneti.com/ProductInfo.aspx?productid=110.4362.41

Already ordered a new one and after waiting for 12 days, looks like her insurance will in fact be paying for it, claims guy finally called me and adjuster is suppose to come by tomorrow.

I may invest in the kit to rebuild old one. Have to check ebay for the going price...how long on the rebuild? And Thanks for the heads up.

It's been about a year since the rebuild and no problems with the master at all.

Thats good to hear.  Ive been fighting with my brakes for about a month now and have no clue whether it is the master cylinders, calipers, or what.  Ive talked to Fred at Yoyodyne a few times and he says there are no rebuild kits for either my master cylinders or calipers - I would have to buy new ones.  He said the rebuild kits available on the Yoyodyne site are "for the vintage crap".  Lol. 

The bike I have is a 2002 M750S.  Rear master is 11mm (I think?), front calipers are 32mm pistons, dont know specs on the rear caliper pistons or front MC.  My parts catalog doesnt say specifics other than part number.  How do I figure out what rebuild kits may work?

If Fred says that theres no rebuild kits for your masters or calipers, he would be the one to know. Might work would not be something I would even consider or suggest, when it comes to brake systems.

Oh I definitely trust Fred - he knows his stuff.  The thing is I asked Fred what Monster calipers/master cylinders ARE rebuildable so the next time, I can just get a rebuild kit rather than the whole thing again. He said none of the Monster calipers/master cylinders are rebuildable.  Brembo recommends getting a new one.  I asked what all those rebuild kits were on the Yoyodyne site then and he said they are not for the Monsters, and though they might "work" he wouldnt recommend them.  I was pretty surprised by that.
But you (M900) and Im sure others have used the rebuild kits with good results

Hooray! Adjuster came by and agree with 100% of damage I showed him, even the helmet that was sitting on the tank when she knocked it over. Anyway Yoyodyne shipped my new MC today and might have it Friday. So I tackled the caliper, took it around the corner to a Yamaha/Honda shop and they hit it with a bit of compressed air and pistons freed up, but head mechanic suggested I split the thing and check out the seals. Having no experience with Brembo, he thought I could find a rebuild kit for it. After looking around the net a bit, seems Brembo doesn't sell rebuild kits. Adjuster and I talked a bit about this issue and having a mechanic do the work til I pointed out that a new one is only $150. Regardless I need to start thinking about putting the rear brakes back together...so will I need to "prime" the MC and the caliper and then begin a bleeding process?

Fred (at Yoyodyne) said that if you are really careful, you can pop the pistons out and clean everything really well but DO NOT split the halves.  You will never ever get them back together and have the seal seated right.