Got a bit of a problem with the back brake on my SY250. Basically it doesn

Is there any fluid escaping from anywhere? I cant see how it could have changed if it has been stood, it may just be coincidence. if the pistons are stuck, you would still have pressure on the pedal, but it wouldnt be grabbing the rear brake so I doubt its stuck pistons.

check all the banjo bolts for tightness aswell as the bleed nipple.

also, make sure that the master cylinder piston is able to release fully, if it isnt doing this then its not letting new fluid back into the system which could be a reason for the poor brake.

failing that, it might be a seal problem, check for brake fluid around the pistons in the caliper and the rear master cylinder.

also check obvious things like the fluid resevoir is filled up!

its possible that if the bike was stood in damp conditions, metal parts (including the brake hose) may have corroded and either let air in or fluit out. might be good to take the whole system off and have a good look around.

Let us know how you get on, id be interested to see where the problem was!

Edit: Just a tip for getting rid of stubborn air in the system, crack the banjo bolts open aswell as the bleed nipple. do it the same way as you would with the nipple but undo the banjo's slightly instead. make sure you keep pressure on the lever when you nip it up though as you will just drag air back in. back bleeding with a syringe is definately better than the conventional method too, just take the brake resevoir off and let it drain into a bucket or keep taking fluid out with a seperate syringe.

Tom

Edited May 27, 200917 yr by tombo46

Thanks for all the info Tom. I ordered a Mitey-Vac to help bleed the brakes. Local shop told me it is really helpful in bleeding stubborn brakes. Also, was told to check rubber hose to resevoir for cracking. I'll let you know what I find.

Thanks again!

Hi

I had a similar problem a few weeks ago on my SY250 2006. I tried bleeding the system, but that did not help. I took the master cylinder apart and all looked fine. After reassembly I took my time bleeding the system and got the air out. I tried pumping the brake fluid in from the caliper but that did not work well, I got the air out in the

Hi

I had a similar problem a few weeks ago on my SY250 2006. I tried bleeding the system, but that did not help. I took the master cylinder apart and all looked fine. After reassembly I took my time bleeding the system and got the air out. I tried pumping the brake fluid in from the caliper but that did not work well, I got the air out in the