Brake bleeding nightmare

[Donor]

Hey folks, apologies for yet another bloody whinge and cry for help...

My front brakes got bounced on a WOF - fair enough, they were binding to buggery and back, so I sorted that out well enough, then bled the brakes and all was good. Now, if I leave the bike for an hour or so, I lose ALL my front brake. It pumps up after a few squeezes, so I'm thinking their HAS to be air in their somewhere, thing is, I am damned if it will bloody well come out!

I'm trying like all hell to get to the testing station before 4pm today, but right now a tin of petrol (4 stroke!) are looking mighty good right now.

Anyone out there got any quick fire hints before it drives me to enjoy my car again?

Tanks in advance folks, and again apologies...

[crashe]

Never apologise when things go wrong on your bike...
Some things are just meant to try us....

Someone on here will be able to help you out........ that's what KB is all about.

You will get the WOF and you will be out there riding your new bike real soon.

[Donor]

Never apologise when things go wrong on your bike...
Some things are just meant to try us....

Someone on here will be able to help you out........ that's what KB is all about.

You will get the WOF and you will be out there riding your new bike real soon.

Thanks crashe... I made the mistake of assuring the guys I am meeting tonight that I would be there on Daisy... I'll be gutted if I don't sort this out, I just know it's going to be something stupid and simple... *sigh*

[crashe]

Thanks crashe... I made the mistake of assuring the guys I am meeting tonight that I would be there on Daisy... I'll be gutted if I don't sort this out, I just know it's going to be something stupid and simple... *sigh*

Take a few deep breathes......... and dont forget to breathe out as well.....

It will all be fine...... maybe worth pm Ixion as he knows quite a bit about bikes... and he lives out south Ak.....

[Donor]

That may be the next step... I've just tried a different method, and seem to have a fair bit more handle... it's hard having been used to them binding, as I don't know what the handle should feel like normally, although I am aware pulling the brake on full at about 10 k's you shouldn't really roll 5 metres before it feels like the bike is contemplating stopping...

Going to go for a skid to the testing station now, might even be some crap on the rotors... who knows? One way to find out, and the back brake works mint... just going to go the long, slow way to be sure...

[Macktheknife]

The only way I know is to top up the master cylinder and bleed from the bottom, slowly squeeze the lever and loosen the nipple, then lock off the nipple and release lever. Repeat until bubble comes out of nipple and keep the MC filled up so you don't suck more air down it.
Or you could go to your local bike shop and ask them to put the power bleeder on it.

[crashe]

The only way I know is to top up the master cylinder and bleed from the bottom, slowly squeeze the lever and loosen the nipple, then lock off the nipple and release lever. Repeat until bubble comes out of nipple and keep the MC filled up so you don't suck more air down it.
Or you could go to your local bike shop and ask them to put the power bleeder on it.

Yep I agree, shoot down to your local bike shop...
pay them $20 to bleed ya brakes... will only take them a few minutes......



OFF topic - Mack how was your shoulder after last week's ride?
As you did the long ride rather than the shorter route to the pub.

[Postie]

If you have bled the brakes, try pressing the brake and holding it on over night with a cable tie. It will help get the air to the top of the system. Its supposed to work and has done for me in the past, someone may read this and say its bollocks, but give it a go your self and see if it works.

[riffer]

I've had this before - it turned out to be air trapped in the top of the line just before the master cylinder.

Squeeze the brake lever up until it becomes rock hard, and then just 'crack' open the banjo bolt on the master cylinder just a touch.

It may just be what you need to fix the problem.

[Paul in NZ]

It's a pretty simple system so IF (big if with neons and flashing arrows) you have got all the air out and then you loose all pressure - air is getting back in.

Have you done this successfully before or is this a first time for you? Sorry if thats an insulting question but it's one of those jobs that seems real easy until it goes horribly wrong.

Assuming there are no leaks or wet places, if you have drained the system you could have buggered a seal or something in the master cylinder?

Check that there is nothing blocking the bottom of the master cylinder.

Check both pads are moving.

If you have an assistant, you can remove the caliper and bleed it above the MC (place something disk sized between the pads) as it helps get the air out.

Best way to fill these things is often from the calipers up or pressure bleed them. A good bike shop should have the tool and it should be pretty simple.

Cheers

[Paul in NZ]

I've had this before - it turned out to be air trapped in the top of the line just before the master cylinder.

Squeeze the brake lever up until it becomes rock hard, and then just 'crack' open the banjo bolt on the master cylinder just a touch.

It may just be what you need to fix the problem.

Thats good advice.

In a complicated system like on the Guzzi's linked brakes you can bleed at each junction along the way - tedious....

[hellnback]

Might pay to loosen the value and pump out the vast majority of the fluid, this should push any air hiding near the top. Then tighten it and rebleed, don't forget to keep the reservoir topped up...

[Motu]

After you pump it up is it hard or soft? - You can't pump up air in the system hard,it will stay spongy.If it stays spongy,then like Paul says it's getting air back into the system through the master cyl.....if it's hard then you are pumping the pistons out each time....so then there is a caliper problem.

[geoffm]

If you can't get it sorted, give me a call and might be able to have a go this weekend.
Geoff

[Donor]

First off, thanks all for the input...

Went up to the testing station, first of all it was a blast having an excuse to get in the saddle, but it got better - they gave me the WOF of joy!

I gave it one last bleed before I left, damned if I could see any air coming out so **HOPEFULLY** it's sorted, although it seems soft to me. Mind you as I said earlier, I have never known what the handle feels like normally, as she was binding something chronic until I spanked the calipers into submission.

Will see what it's like in the morning, if they're soft again, I guess I can only suspect there is air somehow being induced into the system. I might just take you up on that offer Cliff.

Again, thanks all - hopefully my rants and sulks will subside from here on in!