Hi there,

So, I have a GSXR1100 wp and this uses a hydraulic clutch.

This is in the way of the prop, so I have a bracket that moves the slave cylinder backwards. Also I have changed to a ZX9 slave cylinder as it is compact and can be oriented to bleed from the top.

To drive this I have a sv650 rear brake master cylinder and use the standard rubber hose to join the two.

The master cylinder is driven by the pedal directly.

So, I hope you've got all that.


Well it doesn't work so well, but I am not sure why. When I tested all of this on the bench it worked like a dream. Clutch in, change gear, fine.

Now that I have bolted all of this up into the tightest spot in the whole car it isn't playing. The master cylinder is mounted horizontally. I rearranged the hose so it runs up to the slave cylinder (I thought I might have an air bubble), and have bled the system a few times.

So this is what I have got. I push the pedal and there is a slight soft start followed by reasonable resistance. I also get quick "squirting" noise at the point of reasonable resistance. This noise comes from the slave cylinder end of things (could be the hose). The rod that pushes onto the clutch plates (?) does move, but not very far and the clutch stays engaged. Nothing flexes. The total master cylinder motion is maybe 15mm, and the diameter of the master cylinder is 0.5inch (standard rear brake item).

I don't seem to be losing fluid (based on the level after many pushes on pedal).



Has anyone got any ideas?
My list of possibles are:
1) master cylinder doesn't work horizontally
2) slave cylinder seal has gone
3) air bubbles in system (somehow)


Any thoughts appreciated.

Matt

The noise is trapped air. Bleed the system on the bench (slave cylinder movement restricted with a G-clamp) then carry the lot still assembled over to the car and bolt in place. When bleeding the system, tap the cylinders lightly with a hammer to dislodge any air bubbles.

[Edited on 27/1/09 by Mr Whippy]

thanks Whippy,

That makes sense.

It also fits with sods law, as I bought a replacement slave cylinder last night, which assuming it is just air is going to be a "spare" now.

The practice of taking it off to bleed it is much more complicated than the theory. As the space to work in is a bit tiny, and my bracket doesn't easily allow the bolts to be undone. I'll get ready to do some swearing.


Incidentally, do you know if it matters about the orientation of the master-cylinder? On all the bike installs they are angled (even vertical) with the push rod at the bottom. It isn't clear to me whether this is a bike packaging solution, or a requirement of the master cylinder.


Thanks,

Matt

It won’t make any odds what the orientation of a master cylinder is so long as the reservoir is always above it

I am a bit confused now.

If the orientation of the master doesn't matter, and my bleed nipple on my slave is at the top, what is the benefit of doing this on the bench?

I guess I get better access, and can get up close, and stand up straight and it will be warm (alfresco car building isn't the best at the moment).

Yes, I see what you are saying, bench is promising.

Matt

I'd like to add - when attaching the line to the slave/master cylinder, did you check that the line was seated properly before tightening down? I've come across this one before, and given difficult access to the assembly once in the car, wouldn't rule it out as a possibility.

Chris