bleeding brakes - problem

[cymroboi]

done mine on wednesday dave after fitting the master cyl i git off the org.i tried sucking with a seringe and pushing back up and even bleed with the lever ,i was there for about an 1.5hrs but got there in the end left it over night to settel and wala i got a front brake but took me a lot of fu****g about and scratching lol

How are you holding your bike? If its on a paddock stand and is therefore upright, air can get trapped in the banjo bolt/top of the hose at the lever. You can get this out by cracking off the bolt like a bleed valve or you can put your bike on its sidestand and the air will eventually make its way up to the reservoir.

Originally Posted by walkaboutandy

How are you holding your bike? If its on a paddock stand and is therefore upright, air can get trapped in the banjo bolt/top of the hose at the lever. You can get this out by cracking off the bolt like a bleed valve or you can put your bike on its sidestand and the air will eventually make its way up to the reservoir.

+1

i would put money on there being air at the hose/lever joint

push fluid under pressure using the syringe at the caliper end, til you can feel theres pressure there. crack open banjo joint and close straight away, you will hear air come out.

repeat until only fluid comes out. then do the normal bleeding

[Dave20046]

Originally Posted by walkaboutandy

How are you holding your bike? If its on a paddock stand and is therefore upright, air can get trapped in the banjo bolt/top of the hose at the lever. You can get this out by cracking off the bolt like a bleed valve or you can put your bike on its sidestand and the air will eventually make its way up to the reservoir.

It's on it's side stand


Right thanks for your help everyone I'm going to go down and give it another crack armed with a cup of tea, some patience and a dad. I'll let you know how I get on....hopefully I'll get to work afterall tomorrow.

Dave,

Don't keep alternating which end you are doing this from. It's always best to top up and squeeze out. If you've an air pocket in the system, you could just keep moving it from one end to the other, without dispelling it if you keep changing ends.

As Mav says "Squeeze, open close, squeeze, open close" etc. It could take a while, just be patient.

Personally, would advise against allowing fluid to drain through, this method can assist in air getting in. Fluid should always be sucked or pushed through a brake system, not allowed to drain, as by the very nature of draining, air will try to get in. Think of it as trying to get the air out of the middle of a McDonalds straw filled with yummy strawberry milk shake (although please do not try ingesting DOT4).

Essentially, regardless of how you succeed, if you've a deformity in your hose, you need to replace it. Would a visual deformity in a brake hose be an MOT failure folks? Either way, I wouldn't take the chance mate. Better safe than hopeful.

Good luck, hope it's working now.

Originally Posted by Dave20046

It's on it's side stand


Right thanks for your help everyone I'm going to go down and give it another crack armed with a cup of tea, some patience and a dad. I'll let you know how I get on....hopefully I'll get to work afterall tomorrow.

Oh... It may not be lent over enough. Take it off the sidestand and lean over more (without dropping it), count to 10 and then put it upright again. If you see airbubbles rising in the reservoir then repeat leaning over and upright again and again until there is no more bubbles. Then bleed the brakes from the caliper as normal. This worked for me last week when I fitted braided brake hose to mine.

[Dave20046]

Thanks for your comments just spent an hour of squeeze, open close, resqueeze, open close etc. No change

Also bled from the top and bottom banjo bolts.

Didn't try leaning it right over though andy I'll try that tomorrow if I haven't committed suicide

[fizzwheel]

Dave - did you zip tie the brake lever back to the bar, if not go and do that if you have any ties and then see what its like in the morning.

[Dave20046]

Originally Posted by fizzwheel

Dave - did you zip tie the brake lever back to the bar, if not go and do that if you have any ties and then see what its like in the morning.

yeah I remembered to - cheers
I'm starting to reckon over a whole reservoir through the system and no change probably means either a leaky hose or knackered caliper seal.
Bet it's the sunniest weekend ever now..

[fizzwheel]

That made quite a difference to my brakes when I was having similar trouble to you.