docc

Definitely. Is there a part number on the slave? No part number on the Grimeca slave cylinder. There is an outer round section O-ring that is likely the "seal". I'm trying to rule out the inner "flat" O-ring. Again, my failure could be (or could be exacerbated by) the worn flywheel [or input shaft as Chuck noted earlier], but I'm (obviously) hoping for a simple O-ring solution.

The eccentric doesn't offer much adjustment to the pedal position. Maybe something like LuckyPhil has done with his shift lever would give you what you're looking for: http://www.v11lemans.com/forums/index.php?showtopic=19547

Great thread, here, by LuckyPhil on V11 Shift Improvement with lots of photos and good methods: http://www.v11lemans.com/forums/index.php?showtopic=19547

The flywheel wear is a definite concern. I *thought* I was going with the simple solution first. Another high(er) mileage V11 we know of just needed a clutch slave replacement. The failure doesn't *feel* mechanical like the clutch discs popping back out of the flywheel grooves. (But, yeah, I am totally putting off the big teardown. "Some people" seem to take these things apart like Legos ) So, right, the Grimeca made V11 clutch "command" cylinder is No Longer Available.

It's not that it leaks, the clutch won't always re-engage; feels like the piston is sticking.

I'm struggling with the startling statistic that this single solitary seal has stranded my Sport . . . I suppose, if this has happened to two of the three *most used* V11 we know of , it is worth finding a solution for those to follow.

Tomorrow, I'm riding my *Amazingly Reliable* back-up bike with 49,500 miles on it.

Thanks, g! As long as you're fettling the brake control, pull the rubber caps off both ends for a good clean and seal. As gstallons always reminds us: NO petroleum products around brake parts (silicon only)!

That certainly explains the square seal distortion I can see and would further explain why the piston wouldn't retract and the clutch doesn't re-engage reliably. Now, to find that seal: 30mm ID x 3mm square section O-ring EPDM Anybody? [edit 13 July 2017: I don't believe these measurements are reliable.)

Some folks like their pedal higher or lower (I like mine as far down as I can get it to limit over braking the rear). In that case you can set the desired pedal piston, then adjust the actuating rod length to get the freeplay.

On the slippery slope! Before long there'll be peanut butter in the cigars . . .

SSR, assuming it's "South'n", and not "Sierra", would be the "weekend after Labor Day", in the vicinity of Tellico Plains, Tennessee. Get there. Bring tools.

"Damn right, I've got the blues . . ."

YA think? This is what happens when the Sport is down for more than a few days . . . two-weeks-two-days-and-counting . . .

I have emailed Ariete in Varese, Italy, with the details of the application. I'm starting to come unglued with the Sport being down this long . . . [does it show? ]

"EPDM", "Grimeca" and "30mm" . . . That's three of the main food groups right there! http://www.ebay.com/itm/Aprilia-Grimeca-30mm-diameter-two-piston-brake-caliper-seal-kit-12871-PI-/361835872988?_trksid=p2385738.m2548.l4275 Although, both seals are "square" section. Maybe one of them is right for the "flat" seal . . .

Sharin' the copper love . . .

Since this slave cylinder functions just like a brake caliper piston, how likely is it that the "flat" seal is actually square section?

Here's my thinking: With these V11 getting some years on them, and the clutch slave NLA from Moto Guzzi, it is going to be a real benefit to have a source for seal replacement. Most likely, a seal replacement will keep the cylinder in service for a long, long time. I have also not found a Grimeca rebuild kit for this specific application, although there are 30mm brake kits out there. I may have to score one of those and inspect the seals for applicability. BTW, McMaster-Carr also refunded my money. For now, everyone involved is moving toward a reliable solution. Thanks, everyone, for the assistance and education! I have emailed an EPDM seal supplier for a quote on the square section 3mm x 30mm seal. The round section outer seal looks to be 2mm x 30mm.

No leak. Good point about trying to decide what the seal dimensions and profiles are by looking at this 103,000+ mile seal. Let's face it, I don't even know if this is why my clutch won't re-engage reliably. Learning experience, for sure!

Yep: after a little searching I see one supplier specifically states "Buna-N" (Nitrile) is not recommended for auto/ aircraft brake applications. Looks like they need to be : EPDM (Ethylene Propylene) http://www.columbiaerd.com/epdm_orings.php McMaster Carr doesn't seem to have this material in square section metric. Any other suppliers?

I see this in the product description: "They resist hydraulic oils and motor oil." On this page as well: https://www.mcmaster.com/#catalog/123/3550/=18ebml4 What do you think? (Original seal appears "flared", and slightly out of square. )

Yeah, well, $10.80US to have the square section seal made , ten minimum, plus fees. Edit: This could be it: 30mm x 3mm square section O-ring, 70 Durometer: https://www.mcmaster.com/#1171n207/=18e8ya3 If it works, I'll have extras.

Likely the "pawl spring" under the left side cover for the shift mechanism. Lots of good info here the replacement procedure. Not a bad job, really.