Bleeding shimano brakes! What am I doing wrong?
Just spent the best part of 3 hours trying to get a new (old) XT brake working. The hose wasn;t connected to the lever when I got it, and the system was drained. So:Posted 8 years ago
Fitted hose to the lever, with connecting bolt, olive and insert all in the right order.
Followed shimano instructions to fill and bleed the system until no more visible bubbles.
Lever moves all the way back to the bars with the caliper bleed nipple closed and reservoir full and sealed shut. Absolutely no resistance and no visible piston movement. Which implies there's a whopping great air bubble in there somewhere, but I completely flushed it through, and there're no visible leaks.
Any suggestions what I've done wrong would be greatly appreciated as I'm going to miss tomorrow night's ride now 🙁ahwilesSubscriber
for the brake perverts out there, here are 2 tricks of mine:
1) remove the nipple, and wrap the thread in ptfe tape – a few turns will do, this stops any air/oil leakage around the thread during bleeding.
2) put your mineral oil in the freezer over night before use, this will cause a lot of air to come out of solution.
oh, and yes, a syringe is the way to do it – i get mine from boots, the little 5ml ones for feeding/dosing medicine to babies.
is it just me? or is it practically impossible to buy syringes? – i get all sorts of funny looks when i ask for them, maybe i look like a smackhead…Posted 8 years agoluked2Member
is it just me? or is it practically impossible to buy syringes? – i get all sorts of funny looks when i ask for them, maybe i look like a smackhead…
Not just you. At the chemist in the village they looked at me like I was muck. They were fine when I bought a toothbrush.Posted 8 years agocarlphillipsMember
assuming you have done everything correctly, and it still doesnt work then you may have to consder that you have a leakl somewhere, have you checked the hoses for any signs of damage, there could be a leaky piston seal or otherwise somewhere..?
my glass is always half empty btw…!Posted 8 years agoRich_sMember
Having failed to track down syringes from the usual suspects (Boots etc) I wandered randomly into a small chemists on the high street in Middlewich, wandered up to the counter and asked for a 10-25ml ish syringe. Girl behind the counter asked "Oh, is it for a mountain bike?".
At that moment I knew I had a bad habit and sharing needles is BAD 8)Posted 8 years agoPractical MattMember
I pretty much put up the same post about three months ago, reverse bleed is the way to go.
If you're very lucky a nice person from the forum who lives locally will pop round and show you how to do it in return for ale.
Thanks again Sobriety, I owe you one 😉Posted 8 years agoziwiMember
If you can't get a syringe, push the levers a few times until the pistons come quite far out, then push the pistons back into with a screwdriver – you will suddenly see loads of bubbles popping out the reservoir, repeat as necessary. I asked the same question, got that advice and it solved the problem in 10 minutes.Posted 8 years agomboySubscriber
"is it just me? or is it practically impossible to buy syringes? – i get all sorts of funny looks when i ask for them, maybe i look like a smackhead… "
That was the justification I tried to use in boots last time… Still looked at me funny! Maybe they thought i really was gonna inject 25cc+ of scag into my veins in one go, instantly killing myself!
Best bet funnily enough is your local cartridge world… Guess what they use a lot of the time for refilling inkjet printer cartridges! And they've usually got a few spare in stock they'll be happy to sell you for a couple of quid…Posted 8 years ago
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