Scud Posted June 30, 2017 Share Posted June 30, 2017 Outer diameter of cylinder is 40mm at base, and 38mm at the stepped part. The cylinder extends 18mm from the flat surface. 11mm for the thick part, and 7mm for the stepped part. Link to comment Share on other sites More sharing options...
docc Posted June 30, 2017 Share Posted June 30, 2017 Outer diameter of cylinder is 40mm at base, and 38mm at the stepped part. The cylinder extends 18mm from the flat surface. 11mm for the thick part, and 7mm for the stepped part. both holes on the top are the same - 10mm x 1.0 3 fasteners are on 50mm centers piston is 30 mm andy Ok, so, the top holes, mounting holes, and cylinder extensions check out. Could be down to measuring method, but this piston looks to be 32mm and the outer diameter of the "Stepped part" of the cylinder: 37mm Link to comment Share on other sites More sharing options...
bbolesaz Posted June 30, 2017 Share Posted June 30, 2017 Check the O-ring part numbers Link to comment Share on other sites More sharing options...
Scud Posted June 30, 2017 Share Posted June 30, 2017 I used a digital caliper and rounded up to nearest mm. 40mm was actually 39.something; 38 was 37.something. Link to comment Share on other sites More sharing options...
bbolesaz Posted June 30, 2017 Share Posted June 30, 2017 Aren't we comparing cylinders from 2 different Guzzi models? I would assume that identical O-rings would have the same part number. Link to comment Share on other sites More sharing options...
docc Posted June 30, 2017 Share Posted June 30, 2017 Comparing Scud and Andy's V11 cylinder to this one from a 2006-2007 Breva part. The O-rings would have separate part numbers? Link to comment Share on other sites More sharing options...
Scud Posted June 30, 2017 Share Posted June 30, 2017 Moto Guzzi parts catalogs only show the complete slave cylinder - not the component parts of it. The diagrams do show the O-ring for a secondary piston that rides in the rear transmission case, but that is not the O-ring in question. Maybe you could find a Grimeca rebuild kit to compare O-rings? By the way - I want to know more about the spring. I ass-u-me-d that a hydraulic clutch slave would work the same way as a brake caliper, which does not have a spring. Why would a clutch slave need a spring that would apply force in the same direction as the hydraulic pressure? I don't feel like taking a perfectly good one apart. Andy - do you still have the failed one from your bike? Can you pop the piston (probably just needs a puff of compressed air) and see if there's a spring behind it? Link to comment Share on other sites More sharing options...
docc Posted June 30, 2017 Share Posted June 30, 2017 Hey, Scud, measure your piston diameter? Link to comment Share on other sites More sharing options...
Scud Posted June 30, 2017 Share Posted June 30, 2017 All measurements same as Andy's. I only posted things he didn't. Link to comment Share on other sites More sharing options...
docc Posted June 30, 2017 Share Posted June 30, 2017 Seems a piston diameter difference of 2mm might be significant? Link to comment Share on other sites More sharing options...
bbolesaz Posted June 30, 2017 Share Posted June 30, 2017 The clutch has a spring to keep the clutch push rod up against the bearings. Otherwise it will rattle around. On brakes, you want the piston to pull back into the cylinder a bit so the brakes don't drag. My GL1200 hydraulic clutch was just like the V11. My R100GS manual clutch implemented the spring on the clutch push rod lever. Link to comment Share on other sites More sharing options...
bbolesaz Posted June 30, 2017 Share Posted June 30, 2017 2mm piston diameter difference might change the feel of the lever somewhat. More importantly would be if a different piston would engage the spin bearing correctly. Link to comment Share on other sites More sharing options...
andy york Posted June 30, 2017 Author Share Posted June 30, 2017 no spring on any of the other slave cylinders. Quite a few Jap bikes have springs in the slave behind the puck. Link to comment Share on other sites More sharing options...
Scud Posted July 1, 2017 Share Posted July 1, 2017 Hmmm... we are seeing some differences. Here's an illustration with my actual measurements. Link to comment Share on other sites More sharing options...
andy york Posted July 1, 2017 Author Share Posted July 1, 2017 I think we are good on the measurements i have the 1st "step" at 38 mm 2nd "step" at 40 mm depth measured on the outside 18 mm (from the face where the piston is flush to the flange of the unit) inside depth is 27.5 mm first seal is of an o-ring type inner seal is of the square profile o-ring the actual piston dia is 30mm x 24 mm in length Part #s V11 series - GU 01086330 griso/norge FU 05086330 stelvio 978739 MGX 85220R andy Link to comment Share on other sites More sharing options...
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