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Hissing from slave cylinder

Joined Aug 2008
3K Posts | 0+
Brittany France
Just been checking the slave cylinder and when i pull the clutch lever in the slave cylinder hisses:dunno is this normal or is it time to order an MPL one or equivalent??

thanks
 
Hissing??? sounds like the fluid is bypassing the piston seal internally ...or sucking air even?? but doubt that :eek:
Does the clutch function ok?
 
I undid one of the 3 allen bolts on the slave when I was changing the front sprocket, and then i tightened it back up when i had finished with the sprocket change.

Could this let air into the system?

The bike definatley crunches into First now, where as before it was a fairly smooth. I can still find Neutral easily enough though.

Would an MPL slave cylinder fiw crunching into first?
 
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I undid one of the 3 allen bolts on the slave when I was changing the front sprocket, and then i tightened it back up when i had finished with the sprocket change.

Could this let air into the system?

The bike definatley crunches into First now, where as before it was a fairly smooth. I can still find Neutral easily enough though.

Would an MPL slave cylinder fiw crunching into first?

Tim,

You can't let air in to the clutch fluid circuit from what you have done.

Crunching in to first is pretty normal for all bikes when cold, more of a clunk than a crunch really.

Chances are you have reached that point in your ownership time of the bike that you will have to bleed the air out of your clutch circuit. If you have the OE slave fitted then as the bike ages you will have to do this on a more regular basis.

My advice is ditch the OE slave fit an MPL and force bleed it with your new syringe kit. Done this with mine and it has to be one of the best mods I have done so far.

PS. The crunching in to gear may be caused by your chain tension e.g. Too slack. Mine was a bugger to find, I too like you thought it was a clutch issue.
 
Cant we change the master cylinder with another off say a Honda?? and install a MPL unit
 
Think that I have read on the other forums that the Ducati one can be used but you're not going to gain much by replacing it with the Ducati one.

Nothing really wrong with the master cylinder on our RSV's, more of a slave cylinder issue.
 
Think that I have read on the other forums that the Ducati one can be used but you're not going to gain much by replacing it with the Ducati one.

The Ducati one doesn't fit. I was sent a Ducati one from MPL by mistake and it was even a different shape (although it looked OK at first glance). MPL were very quick in sending me the correct one though - which is superb!.
 
just taken the bike out for a ride WOW the 16t made a difference!! doesnt want to hiccup at low speeds now :doug

Spot on AMB67 the chain was far too loose about 30mm adjusted to around 20mm and all is well:thumbup

The gear changes are perfect and I can get neutral first time :doug

I reckon the hissing is the piston expelling air when it moves forward against the actuating rod, although if someone has a standard slave if they could go out and check if they have hissing when pulling the clutch in that would be great!

Thanks for all that replied

Tim
 
just taken the bike out for a ride WOW the 16t made a difference!! doesnt want to hiccup at low speeds now :doug

Spot on AMB67 the chain was far too loose about 30mm adjusted to around 20mm and all is well:thumbup

The gear changes are perfect and I can get neutral first time :doug

I reckon the hissing is the piston expelling air when it moves forward against the actuating rod, although if someone has a standard slave if they could go out and check if they have hissing when pulling the clutch in that would be great!

Thanks for all that replied

Tim

Don´t worry about it. Mine hisses when I use the clutch with the engine not running. I have an MPL MPL slave on mine, and the clutch works perfectly fine.
 

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