2013 Norge 8V Clutch Slave Cylinder Leaking??

[Guzzi2Go]

So I've been reviewing the various threads on the 1200 clutches and slave cylinder. Good general info for my question but not specific.

As I've just completed a swing arm and suspension linkage bearing inspection and grease (they were not too bad) and I've been noticing what I consider sub-par clutch operation, so I've decided to pull the slave cylinder. Question: Should the cavity be dry that the slave cylinder sits fits in, in the rear of the gear box? I found quite a bit a fluid there, looking like the blackish brake fluid that I just bled out of the system last week. As well there was a thin bit of rubber that came from around the piston. You can see the thin piece on the paper towel in the pictures inserted below. My belief is that the seal on the cylinder has failed and hence the cylinder is leaking. Does anyone have experience with this issue and can shed some light on the subject? I presume I will have to purchase a complete unit.

 

[kenrover]

Hi.
It may help to think of a simple hydraulic system like this:
The master cylinder piston is forced (via the clutch lever) along its bore. No fluid should by pass its seal.
Movement of the fluid (largely, fluid cannot be compressed-only subjected to a pressure) pushes the piston at the slave cylinder and that movement via linkages and so on, operates the clutch release mechanism.
Think of the slave cyl as a mirror of the master cyl. No fluid (none) should leak at either end.
Therefore, if there is a leak, the seal on the piston is damaged or has got compromised (gone soft).

Sorry if that's a long-winded explanation. Bottom line is, you may be able to renew the rubbers but that is a waste of time if the cylinder bore is damaged.

FWIW, to over simplify things, hydraulic brakes work in much the same way. Any leak is a bad leak.
Good luck with the repair.

 

[Guzzi2Go]

Thanks Ken: I guess I was thinking more along the line of “is there oil supply from the tranny into this area to lub the thrust bearing”. I’m comfortable working with brakes though I’ve never had a bike with a hydraulic clutch before this one so I was not sure what to expect. But you’re right, if there is no oil to the area then I’m going to have to replace the slave cylinder. Tomorrow I’ll finish pulling things apart to check the thrust bearing. I’ve read quite a bit about the earlier 1200s where there were problems with the thrust bearing. Hopefully that will not be the case here.

 

[V700Steve]

If it is leaking out of rear cover from hole for slave then it will be trans fluid. There is an O-ring on the outside of slave cylinder that stops the oil. AND it has no part # as I remember.

 

[Guzzi2Go]

Thanks yep I've got the O ring out. There was no leaking external to the Slave Cylinder. The fluid was only when I pulled the slave cylinder housing way from the body of the gear box. It was in the cavity and also dripped out a bit from the cavity. The bit of black plastic was from around the piston and seal. Thats what is making me think that the slave cylinder, as a unit, has to be replaced.

 

[scottmastrocinque]

Thanks Ken: I guess I was thinking more along the line of “is there oil supply from the tranny into this area to lub the thrust bearing”. I’m comfortable working with brakes though I’ve never had a bike with a hydraulic clutch before this one so I was not sure what to expect. But you’re right, if there is no oil to the area then I’m going to have to replace the slave cylinder. Tomorrow I’ll finish pulling things apart to check the thrust bearing. I’ve read quite a bit about the earlier 1200s where there were problems with the thrust bearing. Hopefully that will not be the case here.

Think about what you are proposing here…

A hydraulic system is a closed, sealed system. Always.

If you have hydraulic fluid in there, it is because you have a leak. Given the amount of rubber seal you have on your paper towel there, I am not the least bit surprised.