bleeding brakes - problem

[Dave20046]

Originally Posted by flymo

if the seals at the lever were ok before then no reason why they wouldnt be fine now. more than likely air in the system.

Every time I've ever had trouble bleeding brakes its always been trapped air, never a dodgy seal.

Cheers flymo, I actually had this problem after my crash a thousand miles or so ago. In the crash the bike flipped so I'd assumed a bit of air might have got in the system but before I got round to bleeding it a wriggle on the front end and some pumping later...the problem went away. (it doesn't seem logical but I might give this a go)

Sounds like you're getting air in the system somewhere (obviously), as with the nipple open it should just squirt out, however when you release the lever, it'll be sucking air back in.

If you bleed the brakes using conventional method, eventually you should get pressure, however what you do need to be aware of, is if you are using a tube with valve or such, it will only stop air getting back in once the tube is full, unless you suspend it above the bleed nipple as flymo suggests.

If you eventually feel some pressure, you can nip up the bleed nipple (tightly) without letting the lever out, and fasten the lever pulled in with a cable tie and leave over night, when you return in the morning, continue bleed procedure and you should find good resistance.

It is imperative to make sure the reservoir stays topped up, so would advise that you enlist a second pair of hands to make the job slightly easier to keep an eye on it. Check along your hoses for leaks or deformities.

Also, with nipple fastened tightly and lever pulled back and tied, a good minute gently tapping the brake hose, wait a minute and tap again for a minute, can help get air bubbles moving in the right direction.

[Dave20046]

Originally Posted by boot

Sounds like you're getting air in the system somewhere (obviously), as with the nipple open it should just squirt out, however when you release the lever, it'll be sucking air back in.

If you bleed the brakes using conventional method, eventually you should get pressure, however what you do need to be aware of, is if you are using a tube with valve or such, it will only stop air getting back in once the tube is full, unless you suspend it above the bleed nipple as flymo suggests.

If you eventually feel some pressure, you can nip up the bleed nipple (tightly) without letting the lever out, and fasten the lever pulled in with a cable tie and leave over night, when you return in the morning, continue bleed procedure and you should find good resistance.

It is imperative to make sure the reservoir stays topped up, so would advise that you enlist a second pair of hands to make the job slightly easier to keep an eye on it. Check along your hoses for leaks or deformities.

Thanks boot but there doesn't seem to be enough pressure to even send the fluid to the end of a hose. There is a deformity in one of the hoses but it was ther 1000 miles ago with no problem (braid got slightly crushed in the crash) I'll check the lines again but I haven't noticed any.

[maviczap]

I had simlar problems, and sometimes 2 people, one squeezing the lever, the other opening & closing the bleed screw at the right time, can help get an air pocket out of the system.
Don't know if you're trying on your own or with help?

[Dave20046]

Originally Posted by maviczap

I had simlar problems, and sometimes 2 people, one squeezing the lever, the other opening & closing the bleed screw at the right time, can help get an air pocket out of the system.
Don't know if you're trying on your own or with help?

I'm on my own can try and enlist help from my dad but he won't give a **** and might end up being more of a hindrance. he loses attention after a couple of minutes.

How do I know when the right time is to open and close the nipple, magic? Open it, let him start pulling the lever, then as soon as he's pulled it back to the bar I tighten it back up again?

[maviczap]

H'mm well got any mates who can help?

I didn't get mine sorted until I got some help, unless you've got as many arms as an octopus

[Dave20046]

Originally Posted by maviczap

H'mm well got any mates who can help?

I didn't get mine sorted until I got some help, unless you've got as many arms as an octopus

nah they all live in other cities. bloody students. Shouldn't take much longer than 5 minutes might try and coax my dad down

[maviczap]

Well, attach clear pipe to bleed nipple, squeeze b/lever, open bleed nipple, close bleed nipple, squeeze, open,close etc.

just keep the reservior topped up and start with the caliper furthest away from the master cylinder

[jambo]

Patience is a virtue.

Just because you've pushed fluid up through the system doesn't mean all the air's out, just that the first bit of fluid's made it to the top, just like if you bleed from the bottom banjo bolts, the first sign of fluid doesn't mark the end of the air bubbles.

1) Fill the fluid reservoir right up.
2) Open one bleed nipple on one caliper and let the fluid come out through a pipe, fill the reservoir up as necessary. Don't thrash about with the brake lever, just let the flow of brake fluid carry the bubbles out. It's slow but I promise it's working.
3) When no more bubbles are coming out, just fluid, open the bleed nipple on the other caliper, keep topping up the fluid in the resevoir, allow the fluid to flow. Leave the lever alone.
4) Once we've done this, then you can give the calipers a tap with a spanner to try and dislodge any air bubbles, nip up the bleed nipples and have a squeeze to see how it's doing.
5) If it's still squidgy, not you can employ the Squeeze lever, open nipple, close nipple, release lever method to get any last bits out.


Promise it'll work

Jambo