Finally started putting it back together.

[RedexRobB]

Splitters are a pain in the back side on these, I'm not sure why but every one who has probs bleeding nearly always have the splitter.

How are u bleeding the system? I use a vacuum pump, its way better than pumping the lever. You could try unmounting the splitter and turning it allowing the air to move.

The lever shouldn't be able to come back to the bar, not unless you really pull on it. Don't count out the master cylinder either. No amount of good bleeding will get u a solid lever if that's had it.

[Tirpitz]

Rob's right. I had a right song and dance bleeding my brakes when I rebuilt them. I have braided lines and a splitter (yes, I know I should have binned the splitter in hindsight ). I found I had air trapped in the banjo at the MC which was giving me a poor lever. Leave the bike overnight (don't tie the lever back, it's a load of bullocks that 'cure') with the bars on full left lock. In the morning the air will have filtered up to the MC banjo. DO NOT TOUCH THE BRAKE LEVER YET. Get a rag under the banjo, then loosen the bolt, THEN slowly pull the brake lever. Tighten the bolt back up before releasing the lever. You can repeat but TBH one pull should be enough to clear it.

In hindsight a vacuum bleeder does indeed do the job much easier and drags all the air out. Lever pumping doesn't really work as after each pump the tiny bubbles move back to where they were before and you get no-where. You do clear the calipers but the little bubbles elsewhere tend to be difficult to shift.

[Maxticate]

Thanks for all the brake bleeding advice. I left the lever at the highest point as suggested and bled from the banjo bolt but saw no bubbles. I took off the splitter and tapped it and left it so any bubbles should have risen up to the master cylinder banjo bolt. I've also tried vacuum bleeding them and they are still really really poor.

What is indicative of master cyclinder seals needing replacing, other than the brakes being rubbish of course? I saw a tiny bubble in the reservoir right down in the hole where the fluid is pulled through. If fluid can get back to the reservoir when the brake lever isn't pulled how come air bubble can't make it in there?

I'm tempted to try forcing brake fluid in through the bleeders up to the reservoir next using a syringe. is that likely to work?

Really fed up with them now!

[RedexRobB]

When you use a vacuum pump you must make sure the reservoir stays filled with fluid. I assume you are doing that?

yes, you can use a syringe to force the fluid the other way just make sure you dont over fill the reservoir and get it everywhere. Id say sucking it through is easier that blowing (ooer!).

On the master cylinder, was it ok before hand? If it was, its unlikely to have gone wrong unless it always been a bit crap? Otherwise im not sure how you tell, actually

If it were me id have a two line setup and get rid of the problem all together.

[Maxticate]

Not sure what the brakes were like before as I never rode it before dismantling it.

The reservoir has stayed topped up at all times. I tried again, and then tried forcing it the other way with a syringe. Still no good. I've given up with these lines now and bought some HEL full length racing dual front lines.

If that doesn't sort them I can only imagine it is the master cylinder or some crap is in the calipers from when I had them apart.

[ccubed]

Here is an example of how bad the pistons are..

Do you know what that resin stuff is that acts as a pad on the top of the pistons? Not all pistons have it and it prevents the use of a piston remover making dismantling a right pain.

Anyway I repared mine with plastic padding and it seems to work OK.

Also it may be possible to use the buffing wheel to pollish out the damage to the pistons. It will then be possible to put seals back on. Unless it is really really deep corosion the seal will mould to the slightly imperfect but perfectly smooth shape.

[spacebar27]

wemoto.com now offer banjo bolts with bleed nipples built into them. They come in 1 and 1.25mm pitch. i havn't got hold of one yet as i'm away but should solve the bleeding problem.