Master Cyl

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Stillreel

Stillreel

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No shortage of thoughts and opinions on this topic but here's the issue I'm wrestling with now:

Re-sleeved MC results in either soft braking or, after bleeding, the thing warms up to the point of seizing: must pull over and bleed off pressure. Is this a matter of infinite fettling or do I have to go after market Brembo for a reliable front brake? Rather keep it stock but I'm pissed off cuz I got some fluid on the new paint.

BC
 
If it was not doing that before re sleeving then that might be the problem, perhaps a problem at the sleeve and bore or passage from the reservoir to to bore or seal and piston.
Once bled it should not give any problem.
 
What is happening is that the relief hole to the reservoir is being blocked. The piston is now sitting in too far and the seal is blocking the hole. Machine a little off the end of the piston where the circlip retains it and the hole will be uncovered. To prove this, remove the mastercyl and somehow blow from the reservoir. Air should escape from the outlet on the m/cyl. If not, then the hole is blocked as mentioned.
I know this because I modified my master cylinder to my own design. I got it sleeved to 12mm and bought 2 cylinder cups. designed the piston to suit and did it in such a way as to make a separate end cap inside which I could fit or remove shims to get that piston in the right place. I can lock up the front wheel now in a panic if a Metzler ribbed tyre [ this is the correct spelling you Yanks ] is on the front. Have now gone to a TT100 and have not locked up since. Hobot can assert to that as being true.
 
I let Roger at RGM do mine an it works fine. As already said in this thread the seals must not cover the relieve hole so as with the rest of the braking system an other part of the bike the devil is in the details.
 
the original Lochead, with its 5/8 cylinder needs a gorilla to work it. I am only a very small person, not a gorilla, but I can stop as good as a modern bike. I can actually bring the lever back to touch the hand grip. when this happens I can feel the tyre screeming. I still have the original rubber brake hose, and the disc is still original. Didn't cost much to do the m/cyl mod either. If ya got money ta burn. Just burn it. When ya live in the wop wops, ya gotta do what ya got DO. rIDE LIKE THE WIND , RIDE LIKE YA STOLE IT.
 
Stillreel,
I also had the same problem with mine after installing a M/C sleeve kit.All that you need to do is file the part of the lever where it comes in contact with
the plunger a little until you get the proper freeplay.I also did Ludwigs modification on the caliper pistons along with a stainless front brake hose and
you will be pleasantly shocked as to how well it works.I know there are nicer set-ups available,but I wanted to keep the stock caliper and M/C.
YING
 
Hey All;

Thanks so much for the advise. I'll test the "file the lever" theory on Sunday. I had been thinking the issue was the lever was worn too short and had built it up a bit. Maybe I was going the wrong way??

BC
 
Stillreel said:
Torontonian said:
If I had to do it all over again I would go BREMBO.
Click to expand...

The issue with the Brembo is I also have to swap out the signal switches.
Click to expand...

I am just finishing up on a new Brembo bracket that will allow you to retain your stock switch cluster. It will be a a few more weeks before its finished.

Matt / Colorado Norton Works

www.coloradonortonworks.com
 
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