I "pulled" the classic rookie/newbie move and pulled my brake lever while one of the calipers were off the rotor. I managed to pry the pads apart but I had a lot of drag ever since then. So I planned on bleeding but then I dumped my bike and the front lever was banged up pretty bad so I removed the front lever to replace and a couple days days later I noticed that the piston from the front master cylinder itself had protruded and pierced through the rubber cover that it was recessed in before I removed the lever. There is definitely some fluid around the area. Why did this happen???? Is my cylinder done for??????
Here is a pick of what I am talking about.
(http://i78.photobucket.com/albums/j88/uclabiker66/Photo0212.jpg)
Maybe a better picture would make it easier to help out. I can't figure out what it's supposed to be. ???
you should be able to get a rebuild kit for the m/c without too much trouble (never ordered one for a Duc before though)
don't go out and buy a new m/c just rebuild that one, its a very simple part
Okay sorry, that was pretty close. Reminds me of that game they used to play on some game shows when they would zoom in on something and then the contestants would have to guess what it is. Anyways its my front brake master cylinder minus the brake handle. Here it is from the top view. The brownish thing in the middle is the piston coming out of the cylinder! Oh boy.
(http://i78.photobucket.com/albums/j88/uclabiker66/Photo0213.jpg)
There should be a circlip of some sort holding the piston in so you should disassemble and inspect for damage first. Kits may or may not be available. A brand new coffin master from Yoyodyne is around $100-$115. Call Fred at Yoyodyne for availability of kits and/or a new master.
http://www.yoyodyneti.com phone: 973. 3860040
Nope, there is no circlip anywhere at least not that I could see. I wonder why it happened though. I guess I should have emptied the fluid before I removed the lever. [bang] Hopefully this "kit" you mention of is somewhere out there
If it were me, I'd just slap it all together, bleed the line, and take it for a cautious test spin.
Then, reassess the situation.
Are you just assuming there is damage, or do you have reasoning to think so?
No just assuming because THERE IS FLUID AROUND THE PISTON. I'm pretty sure this fluid is brake fluid from inside the cylinder which leads me to believe air has gotten in. But I don't know maybe it will become air tight again when it is recessed back in the cylinder. The good thing is when I tried to push the piston back in it didn't give me trouble.
I will bleed and take it for a spin and then maybe I'll see that everything is okay; but I just don't know. Howie, I'll call Fred and see what he says. I did find the "kits" you mention of so hopefully Fred will be able to tell me which one I'll need. So I guess worst case is that I'll need to buy a kit. It might be a while though before I can take her out for a spin because I am waiting for a new handlebar; mines not functional anymore after I had a tip over. Thanks very much for the help people.
Ask Fred about the circlip also. I have never seen a master that doesn't have some sort of clip to hold the piston in, but I suppose it is possible..
Quote from: uclabiker06 on August 16, 2008, 09:59:04 PM
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I will bleed and take it for a spin and then maybe I'll see that everything is okay; but I just don't know. Howie, I'll call Fred and see what he says. I did find the "kits" you mention of so hopefully Fred will be able to tell me which one I'll need. So I guess worst case is that I'll need to buy a kit. It might be a while though before I can take her out for a spin because I am waiting for a new handlebar; mines not functional anymore after I had a tip over. Thanks very much for the help people.
If it is damaged, this gives you a good opportunity to upgrade.
Unless you aesthetically like the coffin masters, they suck.
Quote
...... pulled my brake lever while one of the calipers were off the rotor. I managed to pry the pads apart but I had a lot of drag ever since then. ........ then I dumped my bike and the front lever was banged up pretty bad so I removed it to replace and a couple days days later I noticed that the piston from the front master cylinder itself had protruded and pierced through the rubber cover that it was recessed in before I removed the lever..
Man, do I know about a series of unfortunate events like this ... bin there ...often..... ???
Quote from: tangueroHondo on August 17, 2008, 10:57:07 PM
Man, do I know about a series of unfortunate events like this ... bin there ...often..... ???
And?
What was your results?
So,what's so wrong if you pull the lever with the caliper off? ???
QuoteSo,what's so wrong if you pull the lever with the caliper off? Huh?
Well thats not the problem because I managed to pry them apart.
The problem is that the boot has ripped because the cylinder piston pushed itself through it. Now, I don't know what purpose the boot serves but I do know that whenever I run my finger across the piston I get a film of fluid on my finger. I know the boots purpose is not to make things air tight because it has a hole in it anyways to let push rod through. Maybe its just there to keep the dirt out.
Just spoke to Fred and he confirmed my suspicions that the boots function is to keep dirt out and that it is not hermetic. Moreover, he said that the film that I was getting on my fingers may just be silicone assembly lube. It didn't burn me at all when a tiny bit got on my fingers so I'm hoping its assembly lube and that I'll be a okay.
Soooooooooooo, when I assemble everything back up if it doesn't function properly I'll get a new cylinder from Fred.
Quote from: dimk on August 18, 2008, 08:36:41 AM
So,what's so wrong if you pull the lever with the caliper off? ???
As mentioned, you can end up with the pads mashed together in the middle of the caliper - with no easy way to get them apart. If you're careful some swearing and a putty knife will get some space bet ween the pads again. But you've got to be careful or you can end up ruining the pads by gouging them or shearing off a chunk of the friction material.
If you do something similar with the clutch slave off, you can end up popping the piston out of the slave body and next thing you know there's a puddle of brake fluid all over
Thanks!
Okay, maybe the thing that pierced the rubber boot in the picture is not the actual piston in the cylinder. The reason I say this is because I did locate a circlip that is holding something back there; maybe that is the piston.
Mystery solved. You are looking at the piston, but the part that extends beyond the circlip and accommodates the pushrod. New dust cap, install and bleed you will be back in business. Of course this assumes you didn't loose the little dowel that touches the plunger on the brake light switch.
Okay, cool, now we're talking. Won't loose the dowel cuz its all loose parts are in a zip lock bag. So can I just pull the old boot off and stuff a new one in there or do I have to open the cylinder up?
Quote from: uclabiker06 on August 18, 2008, 09:31:26 PM
Okay, cool, now we're talking. Won't loose the dowel cuz its all loose parts are in a zip lock bag. So can I just pull the old boot off and stuff a new one in there or do I have to open the cylinder up?
One can never be sure over the interweb, but I see no reason to. Put the lever back on and if all feels good, bleed and you should be good to go.