Back to the Clutch Part II

[scotman]

Work and no garage have somewhat hampered fixing the Jota 120 leaking (dunno?) clutch.

Now got a garage, cover off, dust seal off and I was trying to get the piston out to measure it for bits. So...how do I? It's not just pulling out.

Does the hydraulic hose need unscrewed first ? tried a spanner on it but it's damned tight. Does the little ball bearing I'm seeing yank out? In the meantime, the piston area is soaking in WD40, which is all I've got, and I'm presuming it may or may not be seized... could be the whole problem?

If I succeed I'm guessing at throwing parts at the problem including (made up list from other posts):

? new clutch dust cover
? EPDM slave cylinder O ring
? A (now rotten) felt-looking washer that was inside the cover ? stops crud getting in (?)
? clutch slave cylinder rubber covers (?)
? stainless bleed nipple (?)
? piston/piston kit (?) how do I check if it's worn?
? piston spring (?) debate on here as to lose it or not
? clutch rod balls (one? that's the bearing thing I'm looking at?)

As usual lots of Q's, help appreciated. Cheers, Charlie

 

[Grant]

Charlie, can't you just pump the piston out using the lever and the fluid in the system already? That is the easiest way.
As you have it off the bike just keep pumping the lever until it pops out.

 

[sfcpiet]

Charlie,

Pump it out as Grant descibes..... a bit messy, but easy!

I've omitted the spring with no ill effects.  

Before you remove the piston, check from where the fluid is leaking.  If it's only from the piston and seal, you just need to replace the O-ring.  If it weeps from between the piston and its' housing, the hose fitting will need checking...... if the hose does not seal to the piston housing, fluid will be pressed between housing and cast cover.  The hose fitting must seal to the very bottom of the threaded bore, ie, it doesn't matter if a part of the thread of the hose fitting is still visible!  Many fittings are sealed with a copper washer to the casting, especially when fitted with aftermarket braided hoses, these may(will!) give problems in the long run.

And do be careful undoing the bleed nipple.  Heat and gentle tapping with a small hammer while placing turning pressure on it usually gets 'em out.  Once broken, they're a bugger to repair!!  Not sure if I'd fit a stainless nipple.  These can also sieze in alloy and stainless is not as strong as the stock steel item, probably even easier to break it off.

piet

 

[Simonr501]

1).New clutch dust cover - Wolfgang Haerter, he did have loads.
2).New epdm 'o' ring - same.
3). Stainless bleed nipple - I looked on many US Guzzi/Ducati sites and found a few. I have only nipped mine up and I used anti-seize grease - it does help that I used DOT 5 so I'm not worried by a drip. Check for correct size and thread pitch.
4). Piston Spring? Well mine came apart without one and none went in.

SimonR

 

[scotman]

Thanks guys, now have the piston out and it's a 31mm. Going to order parts today. Couldn't see a clear leak on pulling the clutch, have to presume it's the o-ring, no leaks visible where the cable meets the housing. At the master cyclinder end ("while I'm at it") what might I replace there for a belt and braces job?

And incidentally... what's the best way of getting the old O-ring out... only a couple of mm visible ? was thinking of a toothpick or something so as not to scratch anything. Ta, Charlie

 

[sfcpiet]

As it's already buggered, just use something pointy/sharp to get hold of the old O-ring and lift it out.

You should check if the hose fitting is bottoming on the piston housing/cylinder proper.  This prevents fluid from entering between the cylinder and the casing.  The cylinder is just a press fit in the casing, old, water contaminated fluid can corrode the casing to the point where fluid leaks and the casing cracks under the strain of the pressurised fluid between the components.

If the hose fitting is sealed to the casing with a copper washer, it will most likely not be sealing at the bottom!

piet