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uofabill
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Discussion Starter #1 (Edited)
I just went to discs the middle of June. I believe these are '04 models. Once again the downside of mail order components surfaces.
A couple of weeks ago I took a digger and afterward my front brake has quit working. There was no obvious damage to the brake body (master cylinder) or lever but I must have whacked it when I went down.
The lever would pull all the way to the grip. It develops internal pressure but quickly loses it. Pumping does not correct it.I've re-bled the brake half a dozen times and that didn't fix it so I figure I have damaged my master cylinder. There are no leaks anywhere on the outside of the system.
Yeah I can send it to Hayes but with the freight and the waiting either I will fix it myself or replace the cartridge in the master cylinder.
I downloaded the tech sheets from Hayes on how to service the master cylinder and I tie into the job of disassembly of the brake. I get the cartridge out of the brake body. There was a very small amount of fluid on the bladder but don't appear to be any holes and it appeared that the bladder was in place.
Here's my question, I want to get the piston out of the cartridge but I can't remove the rubber boot that's over the pushrod on the end of the master cylinder. The instructions say to "pull it off over the push rod." I have pulled on the boot to the point that if I continue I'm afraid I'll tear it so I backed off.
There is supposed to be a snap ring behind the boot that has to be removed so that the piston can be removed from the cartridge. Without removing that boot I can't get to the snap ring.
Anybody know how to get that boot off without damaging it?
Also anybody got any ideas as to what I've done to the thing?

Thanks in advance for any suggestions anyone may have.
Bill
 

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uofabill said:
Here's my question, I want to get the piston out of the cartridge but I can't remove the rubber boot that's over the pushrod on the end of the master cylinder. The instructions say to "pull it off over the push rod." I have pulled on the boot to the point that if I continue I'm afraid I'll tear it so I backed off.
There is supposed to be a snap ring behind the boot that has to be removed so that the piston can be removed from the cartridge. Without removing that boot I can't get to the snap ring.
Anybody know how to get that boot off without damaging it?
Also anybody got any ideas as to what I've done to the thing?

Thanks in advance for any suggestions anyone may have.
Bill
Make sure the plastic part of the resevoir is off first.There is a lip on the master cylider where the base of the boot snaps into. So try to roll the base of the boot off the master cylinder first, then pull on the part of the boot that slides on the push rod.
Erik,
Balle Racing
www.balleracing.com
 

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uofabill said:
I just went to discs the middle of June. I believe these are '04 models. Once again the downside of mail order components surfaces.
A couple of weeks ago I took a digger and afterward my front brake has quit working. There was no obvious damage to the brake body (master cylinder) or lever but I must have whacked it when I went down.
The lever would pull all the way to the grip. It develops internal pressure but quickly loses it. Pumping does not correct it.I've re-bled the brake half a dozen times and that didn't fix it so I figure I have damaged my master cylinder. There are no leaks anywhere on the outside of the system.

Thanks in advance for any suggestions anyone may have.
Bill
It is possible to have an internal leak where the hose may have been kinked rupturing the inner liner. Brake fluid will leak into the kevelar sheath under the outer sheath. If you pull the lever hard it should manifest itself in a sudden external leak. Try a new hose before you go into the master cylinder.

Mike
 

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uofabill
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Discussion Starter #4
Thanks for the reply.

It's the plastic part of the reservoir that I couldn't get off.
I have talked to Hayes today and the tech. there told me it slides off toward the hose end of the cartridge. He called it the "multi-purpose piece." The instructions on their website don't mention how to remove that piece, they only say that it snaps in place when reinstalled. I had tried to unscrew it, obviously that didn't do any good. So tonite I'll have another go at it to see I can determine if there's anything wrong with the piston inside the cartridge. From reading their trouble shooting guide it seems that if there is something wrong with the cartridge they just treat the whole thing as disposable and say to replace that entire unit. I've got one ordered.
This is a heck of a weird deal, no leaks no apparent or visible damage to the lever/brake body. But is seems like fluid is leaking by somewhere in the system, most likely in the master cylinder.
Thanks again. If I figure something out I will report back on the board.
 

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uofabill said:
It's the plastic part of the reservoir that I couldn't get off.
I have talked to Hayes today and the tech. there told me it slides off toward the hose end of the cartridge. He called it the "multi-purpose piece." The instructions on their website don't mention how to remove that piece, they only say that it snaps in place when reinstalled. I had tried to unscrew it, obviously that didn't do any good. So tonite I'll have another go at it to see I can determine if there's anything wrong with the piston inside the cartridge. From reading their trouble shooting guide it seems that if there is something wrong with the cartridge they just treat the whole thing as disposable and say to replace that entire unit. I've got one ordered.
This is a heck of a weird deal, no leaks no apparent or visible damage to the lever/brake body. But is seems like fluid is leaking by somewhere in the system, most likely in the master cylinder.
Thanks again. If I figure something out I will report back on the board.
I had trouble the first time removing the plastic multi-purpose piece, I kept trying to pull it off the opposite direction. You may want to check the hose near the lever, the inner lining could be damaged like the other guy said.
Erik,
Balle Racing
www.balleracing.com
 

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uofabill
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Discussion Starter #6
The saga continues!

BalleRacing said:
I had trouble the first time removing the plastic multi-purpose piece, I kept trying to pull it off the opposite direction. You may want to check the hose near the lever, the inner lining could be damaged like the other guy said.
Erik,
Balle Racing
www.balleracing.com
So I finally figure out all the tricks to disassemble my master cylinder and cartridge.
Get inside, wash all the parts with alcohol and closely inspect it all and it doesn't look to me like there is anything wrong with any of those pieces. All the rubber seals and the bladder look good and appear to be in place. So at this point it seems to me that my problem is somewhere else.
It well may be the hose. There is a small crimp at the compression nut. It doesn't look to me like it would be a problem. There is no fluid leaking and there is no evidence of fluid building up between the inner sheath and the outside housing. However fluid is blowing by somewhere and it may be there. I would think that as many times as I've bled the brakes and as much pumping as I've done since starting this process that by now the fluid would be showing up somewhere but maybe not.
I would either have to be the hose or the caliper. I have not disassembled the caliper but I have checked it out as closely as I can and have used a light to look at the outside of the pistons with the pads removed...nothing apparent to me. I pumped the pistons out without the pads and them pushed them back in. that didn't help.
The caliper seems to be working o.k. So by process of elimination that pretty well leaves the hose.
One of the big selling points of Hayes brakes is that "you can get parts anywhere!" I didn't read the small print that says, "anywhere but my town." None of the three LBS here keep any of those parts in stock so I'm trying to find someone here who has piece of brake hose long enough for a front brake. Damn, it's always something.
After the two emails from two of you guys, the hose is the next thing to check.
Stay tuned!
Bill
 

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jeez dude you shoulda just sent em back...i had a problem with mine..called got a RA#....2 day aired em...weds...they recieved fri...they 2 day aired back to me mon i recieved em on wed...total cost $15...oh and they put in a new set of pads..i took em out before i shipped em...pretty good deal i thought.
 

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uofabill said:
One of the big selling points of Hayes brakes is that "you can get parts anywhere!" I didn't read the small print that says, "anywhere but my town." None of the three LBS here keep any of those parts in stock so I'm trying to find someone here who has piece of brake hose long enough for a front brake. Damn, it's always something.
After the two emails from two of you guys, the hose is the next thing to check.
Stay tuned!
Bill
Erik here can sell you a nice set of Goodridge brake lines and you can forget about kinked hoses. ;)

Mike
 

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uofabill
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Discussion Starter #9
Eureka!

Whew, I finally prevailed!
First, thanks for all the tips I recieved here. As a result of those I got the problem solved.
I turned out that it was my hose, as a couple suggested.
As I said in an earlier post, there was a small crimp/wrinkle just behind the compression ring or the jam nut that screws on to the cartridge body. No fluid ever leaked anywhere. I figure that the inner tubing was cracked/split/punctured or something such that either the fluid was going between the inner lining and the outside housing, or was somehow pumping back into the cartridge. At anyrate the fluid would not pump down the hose to the caliper or no pressure would build up. This problem was all in the first 3/16" or less of the hose. If I'd had a new compression ring I could've probably cut off 1/2" and fixed the problem too.
Found a replacement hose, put it on making sure I cut it plenty long (a mistake I made initially), bled the system hit the lever once and it is solid as a rock.
It is possible that I might have tweaked that lining when I assembled the system the first time. Anyhoo, the world looks good today.
Additionally I now am infinitely more knowledgable about Hayes hydro brakes and will not be afraid to tackle any problem that comes up with them. When you get inside them they are really pretty simple.
At some point I will get Goodridge hoses, I bought a set for my son's DH rig and they are not only more durable but their rigidity makes them more responsive, no pressure loss.
Anyway, thanks everyone for all the help!
Bill
 
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