Ok, cool, thanks

My usual method of bleeding involves several feet of aquarium airline, a fag lighter, and some spare brake fluid.

Clean up the bleed nipple if it's dirty or corroded above the flats for the spanner. Get a length of airline that is long enough to go from the bleed nipple to to reservoir, and heat one end with the lighter. Then push the line over the nipple until it won't go on any further. Crack the nipple open with a spanner. Put some extra fluid in the reservoir and put the airline under the surface of the fluid and pump the brake lever. The fluid will now circulate around the system and any bubbles of air will be expelled. If you want to be really adventurous, you could try doing both calipers at the same time. Once no more bubbles come out, you're done, and you can tighten the bleed nipples back up and remove the airline/s. Be careful when doing this as the fluid can go everywhere if you are not careful. Also, be warned that the lines can sometimes hop off the nipples just to catch you out. Once you've sorted the bleed nipples out and drained the airlines back into your container of brake fluid, adjust the fluid in the reservoir to the correct level and replace the cap. If the brake lever is still soft, either you still haven't got all the air out, or something else is amiss. It's never failed to work for me, and I've used this method plenty of times.

Easiest way is to use a mitivac, about £40 but well worth the money

Many ways to bleed the system as noted above.

The vac provides good results and is simple to use. It might seem a big outlay but will make the job easy from then on as they are quite reliable.

Whatever method you bleed though, you need to ensure that your master-cylinder and brakes are in good condition as well as the hoses.

I have stock calipers, almost 12 months ago now I replaced the lines with new braided ones, split the calipers and removed the pistons, replaced all the piston seals as well as the o-rings that join the calipers and overhualed the master cylinder with new parts.

Bled it through properly... Ive washed the brakes off with brake cleaner every month or so just to stop the shit building up on the pistons and you can still stoppie the bike with two fingers no trouble.

Brakes are super fierce if you give them a nudge.

I will be changing the brake fluid soon as it will be 12 months old.. not past its best by a long shot but since it does absorb moisture and most people forget about it until it is past its best, preventation is better than cure.

Air / contaminated fluid are my best guess, if your MC isnt knackered / yu have a leak (surely you wold have seen the fluid)

Remove the cap and suck a bit of fluid out if it is full. brake cleaner the pistons so they are clean and push them abck into the calipers fully (less space for air to get trapped) and try re-bleeding them.

you could always try reverse bleeding? cant go wrong with it. and its very simple.

xivlia wrote:you could always try reverse bleeding? cant go wrong with it. and its very simple.

wow this guy for once is spot on.

i always reverse bleed by forcing fluid in through the nipple with a syringe. piece of piss and no faffing around.
Daves comment on the master cylinder connector too is spot on, can make quite a difference as its a high spot where air can collect.

Great, thanks everyone for the suggestions