I've switched to a 315 master cylinder- the problem is I can't get the clutch to work properly- the lever feel is as if there's air in it, but having chucked a load of DOT 4 through the system- it's still no better. I'm wondering if this could be due to the fact this fluid's been standing for a long time- it looks very slightly milky, OR is it that you need to bleed the clutch "bottom up"?

Thanks

When I fitted my MC I used 2 plastic syringes, one full with fresh new fluid and the other empty to draw excess fluid from the MC.

The procedure I used is this: Find a clear piece of hose which is a good tight fit over the bleed nipple and syringe. Connect the full syringe to bleed nipple using the hose and open it 1/4 turn, then gently PULL the plunger to get any air out of the nipple/hose, this will be seen to enter the syringe and float to the top.

Then gently push the new fluid into the system with syringe keeping an eye on the MC and withdraw excess fluid when needed. Once you have pushed enough fluid into the system, close the bleed nipple. Then try your clutch.

This worked for me 1st time and took less than 10 mins but you have to be gentle with how much pressure you apply to the syringe as the hose can let air in/fluid out depending on how good a seal you've got.

Edited December 20, 200619 yr by Hughesy

I also used a syringe to bleed the MC/Clutch, from bottom up, worked pretty well once you worked it out. Same system on the brakes for my Gas Gas and Beta's,...

And you will need new, fresh fluid.

If it's old, it will have absorbed moisture from the atmosphere, and turn milky, like you describe.

As Hughsey says, you gotta make sure the seal between hose and nipple, (hee hee, i said nipple) is tight.

A small bit of slack will just cause air to enter.

Don't shake the bottle, as this will form air bubbles within the fluid.

Follow Hughseys advice and remember to drain the master cylinder, but not completely, as you need to keep a "head" of fluid

When you're done, get a large elastic band, or a cutting of old inner tube, and tie the lever back to the bars.

While it's tied back, ccasionally go out to the garage/ shed/ living room, and gently tap the lines, from the bottom up, with a spanner. This should get any remaining air out.

Sorted!!

Many thanks for those replies- I have bought some new fluid. I thought I'd found the problem, in the form of a leaking seal between the MC and pipe- but still no good, even with new fluid, hence will wait til I get a syringe- but seeing as 'though I work in the Health care Sector, shouldn't be too difficult- there have to be some perks!

"Bottom(s) Up!"

A vet one is much bigger and easier to use, or tey an independent pharmacy they have catalogues full of bigger stuff.