Front brake took a break
#31
As far as the price goes ... I'm satisfied. I have a brand new part with a warranty, it shipped uber fast, and it bolted on without any modifications to any of the standard mounting areas or lines. I am sure that I could have bought a low-line Brembo for about another $100.00 more, but then I would have had to finagle with lines, a resevoir, a brake light switch and ...
Does anyone know where to buy Spiegler brake line kits at a reasonable price?
#32
I'm sorry for you, and yes.
#34
It gets better, my wife has a math degree
#35
Si senorita! gotcha. My espanol es muy pocito. I understand, yours was broken.
Wow, this is has gotten very interesting.. Thanks for the added advise for checking for air bubbles, and that radial mc looks cool but kinda spendy.
Back to algebra class you two!
Wow, this is has gotten very interesting.. Thanks for the added advise for checking for air bubbles, and that radial mc looks cool but kinda spendy.
Back to algebra class you two!
#36
You said the lever was alwyas spongy?
I don't think you have a broken banjo bolt.
I think you had an air bubble in the brake line all along. the brake lever should feel firm when it's bled properly.
I would say you have an air bubble that finally burped into the master cylinder. That's good news, because it's easy to get rid of now.
there's an orifice that supplies brake fluid to the master cylinder from the reservoir. Take the M/C off and wire it up so the orifice is at the high spot, then press the slave pistons into the calipers. You should see the bubble come out of the orifice because the bubble floats.
Reassemble and pump the brakes back up, making sure you don't run out of fluid in the reservoir.
I don't think you have a broken banjo bolt.
I think you had an air bubble in the brake line all along. the brake lever should feel firm when it's bled properly.
I would say you have an air bubble that finally burped into the master cylinder. That's good news, because it's easy to get rid of now.
there's an orifice that supplies brake fluid to the master cylinder from the reservoir. Take the M/C off and wire it up so the orifice is at the high spot, then press the slave pistons into the calipers. You should see the bubble come out of the orifice because the bubble floats.
Reassemble and pump the brakes back up, making sure you don't run out of fluid in the reservoir.
Ive been swamped with my club and work but tonight I'll be on it. I will try this first, then take apart the banjo fittings to see what it looks like.
Thanks again for that advise. When I replace my brake pads I always open the bleed screw on the caliper so I dont force old fluid back up into the mc. I suspect I dont have to depress the caliper piston very much right?
#37
I think you probably need to bleed the banjo bolt. Reaper and I had trouble getting pressure to build up when he switched to a full RC-51 system. We kept milking fluid out of the bleed valves but never got any pressure. Called a mechanic and he said squeeze the lever and at the same time loosen the banjo bolt slightly. (wrap a towel around it) Then tighten it back down before you release the lever. No problems after that, lever pressurized immediately.
#39
Ok, I did the easy step. Ive bled my brakes for years, didnt run the reservoir empty, soo when i cracked the banjo loose and gave it a squeeze it blew bubbles not only once but half a dozen times. like the entire mc was full of air. weird thing is there was no fluid anywhere on the bike or the floor, so Im still perplexed on this, brake worked fine in November, sat and then this. can the washers on the banjo's go bad? The bolt was tight. I didnt take it off all the way but maybe I should. Anyway, I think I'll still keep my eyes open for a F4i, gixer, RC setup once I decide what setup I want.
I'll leave the lever alone for the night and check it again in the morning.
I'll leave the lever alone for the night and check it again in the morning.
#41
I guess I was a page behind on this thread.
Don't take the reservoir off!!
Take the whole thing off the bar and orient it so the air will go where you want it to go. You probably only have to work with one caliper, if all of the air has made it's way to the top of the hose and into the master cylinder. Think about forcing the air into the master cylinder, then out through the orifice. The orifice is the only place for the fluid to go if you push the slave cylinder in. It works really well. You'll know you're done, when the lever has no spongy peel. It will go pretty solid when the pads hit the rotors.
If you had a leaky master cylinder or piston, there'd be fluid coming out into the world.
Don't take the reservoir off!!
Take the whole thing off the bar and orient it so the air will go where you want it to go. You probably only have to work with one caliper, if all of the air has made it's way to the top of the hose and into the master cylinder. Think about forcing the air into the master cylinder, then out through the orifice. The orifice is the only place for the fluid to go if you push the slave cylinder in. It works really well. You'll know you're done, when the lever has no spongy peel. It will go pretty solid when the pads hit the rotors.
If you had a leaky master cylinder or piston, there'd be fluid coming out into the world.
#43
How did it work out?
I think I could have explained it better:
When the piston in the master cylinder is fully retracted (hands off the brake lever), it sits right on the back edge fo the feed orifice. As soon as you apply the brake the piston slides foreward and blocks the orifice. It can then pressurize the oil in the brake system.
If you angle the master cylinder so that the banjo bolt is angled down at about 45 degrees, reservoir on top, then push the slave cylinder in, it should push the bubble out the orifice (try not to think about sitting in the bath tub, when you're doing this)
Then you'll have to angle it back the other way to get the bubble out the feed tube and into the reservoir.
I hope this helps.
I think I could have explained it better:
When the piston in the master cylinder is fully retracted (hands off the brake lever), it sits right on the back edge fo the feed orifice. As soon as you apply the brake the piston slides foreward and blocks the orifice. It can then pressurize the oil in the brake system.
If you angle the master cylinder so that the banjo bolt is angled down at about 45 degrees, reservoir on top, then push the slave cylinder in, it should push the bubble out the orifice (try not to think about sitting in the bath tub, when you're doing this)
Then you'll have to angle it back the other way to get the bubble out the feed tube and into the reservoir.
I hope this helps.
#44
well, honestly after i bled the master by loosening the banjo bolt, I didnt try your method yet, but will try it.
I feel like a bit of a dork. I spoke with my mechanic friend and he said a small master cyl leak over 3 months may not be noticeable and would indicate a bad seal of the piston or a banjo washer, he didnt look at it, it was just from conversation. Just never thought it would drain dry and not be visually noticeable.
I did talk to another friend who said he had a similar situation some time back. He said he switched from dot 4 synthetic to dot 3 and the brake failed like this one did, he ended up bleeding the entire system and it worked fine. I thought dot 4 and dot 3 were ok to mix. I did add fluid last fall, I dont remember but I may have used dot 3 because im out of the Motul dot 4 now. Anyway Im looking to do the brake upgrade now and will see how that works out. Thanks for all the help.
I feel like a bit of a dork. I spoke with my mechanic friend and he said a small master cyl leak over 3 months may not be noticeable and would indicate a bad seal of the piston or a banjo washer, he didnt look at it, it was just from conversation. Just never thought it would drain dry and not be visually noticeable.
I did talk to another friend who said he had a similar situation some time back. He said he switched from dot 4 synthetic to dot 3 and the brake failed like this one did, he ended up bleeding the entire system and it worked fine. I thought dot 4 and dot 3 were ok to mix. I did add fluid last fall, I dont remember but I may have used dot 3 because im out of the Motul dot 4 now. Anyway Im looking to do the brake upgrade now and will see how that works out. Thanks for all the help.
#45
I can't comment about the brake fluid incompatibility.
An air bubble in the brake line can take a long time to migrate to the top, because of the small ID. Based on what you said about the brake lever feeling soft, I am guessing that it is an air bubble that has been in there a long time.
An air bubble in the brake line can take a long time to migrate to the top, because of the small ID. Based on what you said about the brake lever feeling soft, I am guessing that it is an air bubble that has been in there a long time.
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12-04-2006 04:27 PM