Brake bleeding problems

[mattt]

Hello, I decided to get a set of front and rear Hell braided hoses for my B6 K3. Just fitted the rear hose and added new fluid and I cant get rid of the god damn spongeenes. I bought one of these bleeder valves and the thing doesnt even work, so gone for the manual method. There are two bleed nipples on the rear caliper ive tried bleeding from both and I am not getting any more air out. The brake worked fine with the old hose, Any ideas?



Ps. if it isnt broken, dont fix it.

[tacoman]

I've had the same problem when replacing a line.  Theres so much air to get out there's probably a bubble in there somewhere.  I finally bought a mityvac and you can pump this thing up to really force out the air, much more so than just pumping the brake lever.  Ask around, maybe one of your friends/co-workers have one.  If not, I've heard tapping on the caliper can help dislodge bubbles.  There will probably be more posts with helpful hints or do a search on this site.

[Sven]

I got a little air in one of my lines this weekend when swapping out fluid, and yeah, tapping the caliper lightly with a rubber mallet was the book's advice and it worked, although it took a while to get it bubble-free.

[mattt]

was this on the rear caliper? if so which bleed nipple was the bubble in? Ive used nearly a whole bottle of brake fluid just on the rear brake, still got the fronts to do yet

[Sven]

This was on the front right side.

If the situation is that bad, I don't know that it could get any worse by just letting it all run out and starting over.  At least the inside is well lubed now and air shouldn't stick as much, and the fluid is cheap.

[smooth operator]

Sometimes it even helps to let it set over night,and the air works its way up.

[Red01]

Sometimes it even helps to let it set over night,and the air works its way up.

+1  

You can also coax bubbles along with some tapping - like a screwdriver handle or a soft faced mallet.

[mechguru]

the best and cheapest way ive ever known of bleeding brakes was shown to me many years back in a factory that assembled yamaha brakes ready for fitting to bikes

the big problem with trying to bleed is the fact that the Master cylinder doesnt pump air very far before it has to stop agian and each time it stops naturally it will start to rise again

all you need is a length of clear air pipe like the stuff you use for a fish tank airline.
put this on the bleed nipple and then the other end actually under the fluid level in the master cylinder

undo the nipple and move the level slowly to get fluid into the clear pipe

air will be pushed out into the reservoir and then out into the atmosphere never to return

if left any air will rise back into the M/C or up the clear pipe its as simple as that

if the system is completely dry at the start this method will get it going in no time

once fully bled the fluid can be replaced by letting the old stuff just run out of the pipe and topping up the reservoir with fresh fluid

[blackbandit]

i have used clear pipe and a large 100ml shringe attach one end to shringe the other to bleed nipple
now undo nipple and draw fluid/air through the shringe
dont pump the lever just use shringe
keep the m/c topped up and hey presto the jobs a good un ....
 

[99er]

I've had the calipers complete and still had real difficulty getting small air out of the master. I found that placeing the bike on its sidestand, moving the bars to get the right bar as high as possible and then rapidly tapping the brake lever would release countless tiny bubbles. After 10 minutes of this, the bubbles are no more and the lever is hard as a rock. It's the onlu thing that works for me.
Marc/Atlanta
'99 B12
Galfer cables/Ferodo ST Sintered