docc Posted July 1, 2017 Share Posted July 1, 2017 ID of the cylinder bore? This Breva cylinder is 1.260" on my English-speaking dial calipre. ( x 25.4 = 32mm). Piston length: 20mm Link to comment Share on other sites More sharing options...
docc Posted July 2, 2017 Share Posted July 2, 2017 So, yep: NOPE! The later (Breva) slave won't fit. All of the external dimensions are the same EXCEPT for the "2nd step" (too big on the later model) and the Breva piston is 2mm bigger. (*Might* still work if the "2nd step" wasn't too big to fit all the way into the gearbox case.) Link to comment Share on other sites More sharing options...
docc Posted July 3, 2017 Share Posted July 3, 2017 I can see these marks, but can't feel them. Even after cleaning and lubing it, the piston doesn't slide back into the bore very easily. Link to comment Share on other sites More sharing options...
gstallons Posted July 3, 2017 Share Posted July 3, 2017 If you want to , you can use Scotch-Brite to smooth up the surface . p.s. use the most fine pad you can get . Clean up w/Brake-Kleen , reassemble with brake assembly fluid and you will be good. Link to comment Share on other sites More sharing options...
docc Posted July 3, 2017 Share Posted July 3, 2017 I'd like to find these two simple seals . . . [edit: I asked the ebay seller about returning the Breva part and he immediately refunded my money. So, 1) if anyone needs a Breva clutch slave, I'll send it to you, and 2) David at Redlands Cycles in Oregon City, OR, USA is top notch (ebay seller: gsmess ) Link to comment Share on other sites More sharing options...
docc Posted July 3, 2017 Share Posted July 3, 2017 Well, the good news is I got the slave off without too much drama: removed only the exhaust system behind the header tubes (in one piece), and managed to get the hex drive fasteners out with a little heat and a few hammer/ drive taps, and removed the slave working from below with the V11 on the lift all the way up. (I had dreaded this job thinking I would be pulling the swingarm and drilling out the fasteners.) Took the seals to my local rubber/gasket supplier and they will have vendor spec them (and build the square section seal if necessary), after the holiday. Link to comment Share on other sites More sharing options...
swooshdave Posted July 6, 2017 Share Posted July 6, 2017 I'd like to find these two simple seals . . . [edit: I asked the ebay seller about returning the Breva part and he immediately refunded my money. So, 1) if anyone needs a Breva clutch slave, I'll send it to you, and 2) David at Redlands Cycles in Oregon City, OR, USA is top notch (ebay seller: gsmess ) Never heard of him. And I thought I knew everyone in the area. Link to comment Share on other sites More sharing options...
docc Posted July 6, 2017 Share Posted July 6, 2017 I'd like to find these two simple seals . . . [edit: I asked the ebay seller about returning the Breva part and he immediately refunded my money. So, 1) if anyone needs a Breva clutch slave, I'll send it to you, and 2) David at Redlands Cycles in Oregon City, OR, USA is top notch (ebay seller: gsmess ) Never heard of him. And I thought I knew everyone in the area. Online store only. I don't think they have a brick-and-mortar store. There was some confusion about the nomenclature (for Moto Guzzi? Really? ) and the guy just immediately refunded my money and took down the Breva parts until they could figure it out. I suggested there is no "V" in Breva 1100 and certainly no "V11." Link to comment Share on other sites More sharing options...
docc Posted July 7, 2017 Share Posted July 7, 2017 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. Link to comment Share on other sites More sharing options...
gstallons Posted July 7, 2017 Share Posted July 7, 2017 Docc , take a look at what this seal is compatible with . It lists mineral oil and a lot of others sans brake fluid . You will HAVE to use DOT 5 silicone fluid if you do . How bad is the original seal ? Link to comment Share on other sites More sharing options...
docc Posted July 7, 2017 Share Posted July 7, 2017 Docc , take a look at what this seal is compatible with . It lists mineral oil and a lot of others sans brake fluid . You will HAVE to use DOT 5 silicone fluid if you do . How bad is the original seal ? 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. ) Link to comment Share on other sites More sharing options...
gstallons Posted July 7, 2017 Share Posted July 7, 2017 I hate to tell ya , the only thing that is compatible with brake rubber is brake fluid , DOT 5 silicone brake fluid , brake assembly fluid , water , isopropyl alcohol and a few other things I don't know about . Petroleum products are off the list . I am not a good influence , put it together and see what happens. Use some brake assembly fluid from a auto parts store when you reassemble . Link to comment Share on other sites More sharing options...
docc Posted July 7, 2017 Share Posted July 7, 2017 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? Link to comment Share on other sites More sharing options...
swooshdave Posted July 7, 2017 Share Posted July 7, 2017 Did the old seal leak? Some seals you think should be square actually aren't. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
docc Posted July 7, 2017 Share Posted July 7, 2017 Did the old seal leak? Some seals you think should be square actually aren't. Sent from my iPhone using Tapatalk 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! Link to comment Share on other sites More sharing options...
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