Front Master Cylinder Bleeding

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hobot said:
My sleeved Lockheed m/c jets fluid. Might help if you check with vendor what is expected from your custom m/c. Old swollen hose can feel soft but assume that is not the instant case. I zip tie my lever to grip with bars turned to rise m/c and leave in over night to let the adhering bubbles slowly crawl out and disperse. So far seems to give me full solid connection of effort to effect. Even filling from bottom up can't eliminate these tiny bubbles that still can add up to enough volume to annoy.
Vibration can help shake them loose but they still take their sweet slow time to rise and disperse. Hope that's all you issue is.
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In the video I made a point to show the complete setup, stainless line and all. Not to show off but to show what the variables are. Damn bubbles. The kid likes bubbles, me? Not so much... :mrgreen:
 
I got one of these little item at a med supply house for $30. Don't ask what it is for (I really do not know, but can imagine). Stick the hose down on the bleeder, turn it on, open the bleeder. Keep a full bottle of fluid at the MC and bring in the lever to where the bubble show. In no time the system will be tight.
I think that when rebuilding the caliper, so much void needs to be filled and the lever alone takes for ever to get the done.
Make sure to vessal is clean and you can return the fluid to the container. I have used it many time on many things(brake related). I am never shy to mess with the brakes with this thing on the shelf.
Front Master Cylinder Bleeding
 
hi Dave
Have you put some PTFE tape around the bleed nipple threads so that you get full suction on the fluid.
 
Wow, that is some fancy machinery. I use a piece of clear tubing and a little plastic bottle as a catch basin for the fluid, cost about 2 bucks. No fancy gun, gauge or aqualung. I don't put tape on the bleed nipple threads either. Dave, you must have other issues in the system because if I can bleed a norton anyone can bleed a norton and there is no special trick to it other than what I said above, no ribbing intended either.
 
britbike220 said:
Wow, that is some fancy machinery. I use a piece of clear tubing and a little plastic bottle as a catch basin for the fluid, cost about 2 bucks. No fancy gun, gauge or aqualung. I don't put tape on the bleed nipple threads either. Dave, you must have other issues in the system because if I can bleed a norton anyone can bleed a norton and there is no special trick to it other than what I said above, no ribbing intended either.
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Me? Issues? Probably.

Are you bleeding from a dry system? That can make a difference.
 
KEV-C said:
hi Dave
Have you put some PTFE tape around the bleed nipple threads so that you get full suction on the fluid.
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I removed the bleed nipple completely and used of of the vacuum bleeder attachments before I finally got all the air out! :wink:
 
Dave, I was laughing about all the attachments for the gun and that vacuum in the post above yours. I merely remove the master cylinder cap make sure the reservoir is full at all times and pump the lever as stiff as it will go, hold the lever, release the bleeder and repeat. The clear tube is attached to the bleeder. I watch to make sure the bubbles don't travel the wrong way in the tube and continue this until the bubbles are gone. I do take the caliper and try and turn it in different directions to get some extra air out of the system. I was only thinking that if this general process isn't working there are issues elsewhere. My front brake is usually bled within 10 minutes of pumping and refilling the reservoir and I usually go through at least a bottle and a half of brake fluid.
 
Way too much travel. Bleed again and bungee the lever to the grip over night. That should get all the air out.
 
britbike220 said:
Dave, I was laughing about all the attachments for the gun and that vacuum in the post above yours.
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All the attachments are because that device can be used for both brake bleeding and checking vacuum lines. Very handy.

Again I think there's a big difference between a wet and a dry bleed. But I'm glad it works for you. I'll get it sorted soon. Even with my contraption.
 
swooshdave said:
britbike220 said:
Dave, I was laughing about all the attachments for the gun and that vacuum in the post above yours.
Click to expand...

All the attachments are because that device can be used for both brake bleeding and checking vacuum lines. Very handy.

Again I think there's a big difference between a wet and a dry bleed. But I'm glad it works for you. I'll get it sorted soon. Even with my contraption.
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I use the same Mityvac kit. Starting from dry it's a lot faster to get the system filled and fully bled than endless lever pumping.

It's also good for recovering primary chaincase oil.

Top kit.
 
Whatever works for you. It just struck me as funny all the fancy stuff used to bleed brakes when all you really need is a tube, a jar, a wrench and a strong grip, old school, sorry. :mrgreen:
 
Turned the bars to the left (it raises the master cylinder to it's highest point) and clamped the lever back last nite. Checked it this evening and it's feeling better. I'll check again tomorrow. There is hope... :mrgreen:
 
Dave,
I used to see the same problem on a certain variety of Yamaha quite often.
Twist the bars so that the master cylinder is at it's highest. Wrap an elastic band around the lever and the bars so there is constant pressure on the lever. Not too much just a light grab. Leave it overnight an voila....perfect feel.
 
[video]http://www.youtube.com/watch?v=X15Yca0DVlo[/video]

It's getting better. Finally something on this bike that you actually don't touch and it fixes itself!

It may not look like it but it's starting to feel firmer. <insert inappropriate joke here>
 
Beginning to sound like kill switch or Boyer bother. Have you not yet just tied lever back with bars turned to elevate m/c and checked next day. Of course I totally understand the immersion to wallow in every nuance hang up first few times around.
In my case layer of almost microscopic bubbles adhere to surface and just take their sweet time to rise even if totally free of surface, so small they barely creep up and out. I'm one of the few who think-find plain stock disc brake perfectly effective at high speed like ABS anti-lock till about 55-60 can lock up at will with a fear level grip. Well actually I think the factory brake is a bad as everyone else complains until the factory restriction removed. With your current method you may expect good feeling brake within the next 2 wk.
 
hobot said:
Beginning to sound like kill switch or Boyer bother. Have you not yet just tied lever back with bars turned to elevate m/c and checked next day.
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Yes, that's what I'm doing.
 
Dave, the reslieved MC's from Al miles can be a pain to get set up. Do you have a copy of his mounting instructions? The little tiny Allen set screws that adjust the backing plate and the "non" threaded through bolts that mount the thing need to be just right or it's a pain to bleed and will fail after a while. After adjusting it by Al's direction I still had to leave the lever tied to the handle every night for a few days to get all the air out but once done the handle is solid right from the start. I still don't fully trust it though. I think the real solution is called "Brembo"!!!
 
A Brembo master cylinder will give little or no better performance than any properly sized master cylinder with lever ratios being the same. The single most important criteria is the ratio between caliper(s) and master cylinder. See http://www.vintagebrake.com/mastercylinder.htm for proper ratios.
 
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