Bleeding Front Brake

I guess air can move through places where a liquid might not. And since the system never builds any amount of pressure with air still present, the fluid stays in. That's my theory anyway
When I was experiencing the problem I found an old thread here where one of the posters cured his brake bleeding problem by changing the sealing washer. He also had continuous air pulling in on every backstroke, but no fluid leaking from the joint.

Glen

if you are using a full length braided hose

remove the caliper and suspend it above the master cylinder trapped air then rises , jam the pistons back with a piece of wood

then ask a buddy to pump the lever whilst you operate the bleed nipple once you fill the system it should bleed OK

if you are working alone use an auto type easy bleed that works of a spare tyre pressure

Back in 13 when I rebuilt my Lockheed I did a complete rebuld from the caliper up and bled from bottom up with a syringe as per the article in Old Britts. It worked fine and no air, but after a few months of sitting the fluid completely drained out. Pretty much told me to upgrade the front brake system. Not sure why it bled out but I figure just after almost 40 years the pistons had enough work on it the cylinders were not exaclty fitting snug. When you rebuilt the master cylinder did were you able to get all the little holes cleaned out good? I picked and scraped and used a lot of compressed air to ensure all my hole were clear. Just my 2 cents. Hope you get working soon, weather is too nice to not get some road time!

I clamped the lever back and checked it this morning. Keep in mind there was no pressure at the lever at all.

Lo and behold... I'm guessing it's 80% there. I have never seen anything like this. I've had partial pressure and left it clamped but no pressure?

I'll leave it clamped for a few more days and see what happens.

:shock:

Works a treat don't it?

You might also try tapping the caliper and the brake line lightly with the plastic or wooden handle of a screwdriver, working from the bottom up. Encourages those last little sticky bubbles to migrate up to the MC.

Glad you seem on your way Dave.

Yep, just another one of the many Norton specific idiosyncrasies that make no sense in the non Norton world but are just part of the stuff we learn. These are the kinds of things that make it very hard to trust anyone other then a Norton specific shop. I'm now using a Brembo MC with my stock but rebuilt caliper & braided line & still had to do the clamp the handle thing to get the last bit of air out. Glad you got it working Swoosh, Now since your not using it do you want to sell me that alloy Dunstall type tank??? I really dont want to use my glass Prody racer tank.. Glenn.

gtsun said:

Yep, just another one of the many Norton specific idiosyncrasies that make no sense in the non Norton world but are just part of the stuff we learn. These are the kinds of things that make it very hard to trust anyone other then a Norton specific shop. I'm now using a Brembo MC with my stock but rebuilt caliper & braided line & still had to do the clamp the handle thing to get the last bit of air out. Glad you got it working Swoosh, Now since your not using it do you want to sell me that alloy Dunstall type tank??? I really dont want to use my glass Prody racer tank.. Glenn.

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The aluminum tank will go back on after a while. Just switching it up for now. :mrgreen:

Yesterday I shortened my front braided brake hose and had the same problem. No amount of conventional bleeding + lever-pumping would achieve any firmness in the handle at all. I finally used my MityVac at the caliper bleed fitting and quickly got to around 75% firmness before running the reservoir low on DOT 3, so I just tied-back the lever with a zip-tie and this morning it instantly pumped-up to full firmness. Just my $.02

mschmitz57 said:

Yesterday I shortened my front braided brake hose and had the same problem. No amount of conventional bleeding + lever-pumping would achieve any firmness in the handle at all. I finally used my MityVac at the caliper bleed fitting and quickly got to around 75% firmness before running the reservoir low on DOT 3, so I just tied-back the lever with a zip-tie and this morning it instantly pumped-up to full firmness. Just my $.02

Click to expand...

I was using the MityVac too but never got it to do anything.

I use one of these to clamp the lever back. Quick and reusable. :mrgreen:

swooshdave said:

..........I use one of these to clamp the lever back. Quick and reusable. :mrgreen:

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I have a bunch of different sizes of those clamps, and I find them very useful too, I tried some from harbor freight but they fell apart fairly quickly after buying them, the Irwin ones have lasted for years