I had exactly the same problem, leaky reservoir seal. Part seems to not be rebuildable/ seals not replaceable/ individual parts not available separately. If you want the same one, you have to replace the whole thing. I think it's a common issue with the stock masters. Seems to me like a pretty poor design, with that proprietary reservoir. Even if you find a good condition used one, it will no doubt start to leak at some point in the future. If you have the coins, why not just replace it with a good one?

I replaced mine with a Brembo 19x20 master. Like (firm) buttah. Stop on a dime and you can tell if it's heads or tails. Not rock hard, not mushy, just right.
The forged ones aren't that expensive (~$240 here in the states), and they are rebuildable if you need to in the future.

 

Brembo does sell the remote inlets for all of the GP master cylinders as a separate part. Perhaps the seal is included, and is the same size? Check the TAW Brembo website for the different part numbers

 

Thanks guys

I have a found a 999 clutch reservoir kit which has a similar seal in it. I am getting it next week and hopefully the seal fits.

I have found a vendor in UK selling the remote adaptor fittings and it looks like the seal is included. Seal looks very similar. I am awaiting a response from them. Only about 4 pounds each.

Wayne

 

I realize I'm resurrecting a zombie thread here--but I emailed Steve at Bevel Heaven and he offered this as a solution. He says the seal that comes in this $13 kit will fit on the reservoirs of my '05 ST3 (similar style master).

Bevel Heaven Vintage & Classic Ducati Restoration & Spare Parts (925)798-2385

These elbow kits will fit all remote reservior BREMBO master cylinders. They are not too difficult to install but if you have an obsolete master cylinder and your elbow is broken and leaking, here you go, you finally have an option. After removing the old elbow and oring seal thing, lube up...

store.bevelheaven.com

 

I ended up getting a reservoir kit for a 1000MTS that had the rubber grommet in it. Pic attached