chris plant wrote:hi bigstu,you mentioned everything but the flexible rubber hose,i had a similar problem and it turned out to be the hose had collapsed inside

Older hoses have a tendency to delaminate, where the inner lining cracks and pulls away from the wall of the hose. Fluid pressure makes this lining flap over like a valve, and cut fluid flow. A hose like this is hard to bleed and makes for spongy or dead-feeling brake action. If the hose has any signs of cracking on the outside, this is a real possibility on the inside.

When I first reused this hose on rebuilding, it was blocked and I had to force the blockage free by use of the master cylinder to blow it through. It is not in great shape. I think it may have delaminated as you describe.
I will replace it with a braided hose if I can.
I have no problem bleeding the system with the other master cyl (off a Suzuki GT750), and I also have no problem with the new master cylinder if I just block off the banjo exit on the master cylinder, so it is not leaking internally.
I need to make up a flexible hose that is m10 x 1 pitch at the master cylinder and whatever the thread is that goes into the caliper (Grimeca 2 pot from RGM). Then we will try again.
I am running again with the Suzuki master cyl until then.
By the way, can you knacker your pads by contamination with brake fluid?
Stu.

bigstu wrote:When I first reused this hose on rebuilding, it was blocked and I had to force the blockage free by use of the master cylinder to blow it through. It is not in great shape. I think it may have delaminated as you describe.

Good information to know when you first described the problem.

By the way, can you knacker your pads by contamination with brake fluid?
Stu.

About as ideal as the crappy hose. Maybe worse.

As far as brake fluid contamination on pads it can often be removed by washing the pad with soap and water to get rid of excess fluid and sanding until clean material shows. One time that did not work for me on porus pads but it usually does.

Hi JimC
Finally got the 11mm master cylinder bled with the help of another set of hands. Also used a braided hose.
Tested last night. You can pull the lever almost back to the bars at standstill if you try, just like a modern system.
On the road you need one finger to pull the bike up.
Now I need a fork brace!
Thanks Jim, if it wasn't for your advice I would have gone for 13 of 14mm piston diameter as per RGM advice.
Stu.

bigstu wrote:Hi JimC
Finally got the 11mm master cylinder bled with the help of another set of hands. Also used a braided hose.
Tested last night. You can pull the lever almost back to the bars at standstill if you try, just like a modern system.
On the road you need one finger to pull the bike up.
Now I need a fork brace!
Thanks Jim, if it wasn't for your advice I would have gone for 13 of 14mm piston diameter as per RGM advice.
Stu.

Now, you too, have a great front stopper. I didn't figure this out by myself. I used the vast knowledge of Michael Morris of Vintage Brake. The man KNOWS brakes. I just passed it on. BTW, I always had a very poor rear drum brake. Sent it to Michael and got back an excellent rear stopper.

if it wasn't for your advice I would have gone for 13 of 14mm piston diameter as per RGM advice.

Unfortunately, some of those who sell Norton parts don't know apricots from horse apples. Two very reputable houses I've personally dealt with come to mind. One was developing a wide swing arm for the Commando to accommodate a wide rear tire . When I asked what he was going to do about the chain to tire clearance he was stumped. Later he tried to press his particular political ideology upon me, with less than good results. I told him where to put his parts. If I don't have first hand knowledge I usually get more than one opinion before I fork over my cash for a part.

grandpaul wrote:The hand-operated brake bleeding pump kits are invaluable.

You can use both the pressure and vacuum features to ensure ultimate success.

I agree that is my prefered method its quicker and the kits are pretty cheap

Another method in obstinate cases is to use the syringe to 'suck' the fluid down from the m/cyl to the bleed screw,
Dave.

Where can you get these cheap kits online?

Google search for "suction bleeder" currently shows some on Ebay for about £40. Snapon Tools do a Blue Point kit but their site is down until next week. My Blue Point kit usually works ok, although it failed to bleed last time for me until I had removed the front wheel, swung the caliper with bleed nipple vertical and hung the master cylinder above the bars in such a way that no pipe bends could contain trapped air bubbles. Hassle, but it worked fine. I guess it depends on the orientation of the hydraulic parts of each particular bike / handlebar / caliper etc.