It has come to my attention that after market cylinders do not actually fit all bikes from 1990 up to the Panigale. The cylinder in the 620ie looks quite different. Does anyone know what the story is here? What other engines are like the 620ie? Here is a 620 cylinder https://www.ebay.co.uk/itm/Ducati-M...614694?hash=item36305cafe6:g:aE8AAOSwM91aku2D Here is the 'standard' cylinder https://www.ebay.com/itm/Ducati-900ss-Monster-slave-cylinder-STM-/323052939924
That 620 cylinder is the same as most other Ducatis from around 1999 with 3-phase alternators, the 'Standard' cylinder is from the earlier bikes. Aftermarket slaves usually come with a small spacer to be used with the older bikes to make up for the difference in pushrod lengths. There was a further change around 2010 when Ducati started fitting anti-rotation pegs to the pushrod which engage with a slot in the slave cylinder, preventing the pushrod from turning with the clutch. Current Oberon replacements have this slot.
So the aftermarket ones all have a flat back, meaning dirt will get to the seal on bikes from about 1999?
The spacer sits in the body of the slave cylinder. I have fitted Oberon to all my Ducatis and all of them have used a small green o ring to seal the case/slave mating face. Andy
This still leaves concern to me. None of the after market ones look like pic 2 and 3, both of which have a protective collar to stop the shit getting anywhere near the seal I think?
Never had an issue with the Oberon on a 996, 748sp, ST4S, 748R, Multistrada1200, 853RS or 1098R. Andy
Here is an illustration of mismatch..this Avanti one has the same back as Oberon's, ie it is flattish. It fits well, it works well....but look at that gap near the chain.
The Oberon slave cylinders I have fitted have all compressed the green o ring, without exception. Andy
Rich, the primary seal is the one inside of your slave cylinder in the same way as the seals within your brake calipers. The crap won't bypass this to get into the inner workings, and if it does then you've probably got bigger problems anyways as the seal will have already broken down. With a radial master it will move no more than 2.2mm so the piston will never by pushed out far enough to be a concern given the relative position of the seal inside it. If in doubt might I suggest a case saver? After rebuilding a gsxr engine which had suffered a chain strike i'll never underestimate the value of these and it will probably do the job of being a pretty good crud catcher as well. The other option is to squeeze a ring of grease into the gap to act like a wet seal.
