Brakes Lever Pulls Flat

Greetings.
I have had a problem with my 08' K9 front brake that has gone on for a long time with no one having a solution. Apprantley, it always gets air in the line, then I take it to the shop and they bleed it and its okay for about 500-1000 miles at best and then it starts by losing the lever a little at a time until eventually it will go to zero and I will have no front brakes at all.

Most recently they even put on new pads (the old ones still had pad) and new fluid (I have ran through a lot of fluid here over the years) and I had a full lever. Now it is once again starting the same trick as it starts out gradual until it progresses to zero brakes. The only thing new this time is that it is leaking out fluid. The first time it leaked out was with the handle bars turned around and now it is just leaking out drops around the bottom but still leaking. I know they tried to get in as much fluid as possible likely over filling.

Realize that the shop is doing this not me as I don't know what to do about it and have no solution. Any help or suggestions would be greatly appreciated. I feel certain I am not the only one who has had this problem?

Thank you, T.
 

Th3InfamousI

Administrator
Staff member
Lifetime Supporting Member
Supporting Member
A lot of time that gasket is a problem.

Sent from my 2PS64 using Tapatalk
 

Nཛ͢ཀཇཧ༏ཧי

... .... .- .. -.
Lifetime Supporting Member
Supporting Member
First thing I'd do is make sure the brake line is tight at both ends. Then replace the bleeder screw on it. If that doesn't fix it, the rebuild the caliper. I'm most suspect of the bleeder.
 

Unsprung

In the Potters hand...
Which shop are you using? There's a place in Ybor City called Ride Factory who mount my tires and have helped me with my carb. Check them out if you don't wrench on it yourself.
 
Thanks Guys, are we talking about the leaking or the air or both are the same. Realize they just replaced the brakes and fluid. Also this is the first time it has ever leaked. I don't work on it myself but these guys are not some bozos either and they have been with this bike for years so you would think they would know and do the obvious. However, I will ask about the items mentioned here. I was thinking perhaps I should have the master cylinder rebuilt? No one has mentioned the caliper or any problem in that area and they have spent some time around it. However, if no one has had these symptoms I will have to try the shotgun approach I guess, which is to start replacing and rebuilding things. I don't see anything obvious and there is no leakage around the caliper area. This has been going on for a very long time and over that time some good people have looked at it yet no answers have been forthcoming. I wish I could blame it on the competence of the people caring for the bike but I can't. So I am trying, hoping for a common experience..

Thanks for your prompt responses as I can no longer chance riding the damn thing. One stop I have brakes and the next not so much...T
 
If it were only that simple. However, as I mentioned in my original post this has been going on a long time and this "leak" is new. I think it was overfilled on purpose and this did not work. The leakage is from around the lever/master area which I saw filled to the top. So its not as simple as a leak since its been doing this for a long time. It goes along for a while but always comes back to this problem again. I go for the lever and it just pulls all the way back. They even put new shoes on it. I know it sounds as if it is an obvious problem, but its not. No one has solved it for more than a limited time. One person said that it was due to the placing of the bleeder hole in the cylinder and that the fluid at times would "run" away from it and leave "air". Or something like that, I will go find that invoice and put in here exactly what was said/found by a tech widely believed to be one of the best in this area. T
 
I quote: Customer states brake lever pulls all the way back at times-/ Inspected brake system/found fluid in brake master cylinder running away from the bleeder hole and letting in air/Result: Topped off with fluid-End Quote this was over 3k miles ago and its done the same thing about at least two times since then including this last time which was only 500 miles ago (one month) now it has started in that direction again. That is right off the invoice. Then the owner decided we should try new pads, okay that was great for a while. But this is the first time fluid has ever leaked or at least so that I was aware of it and I would be aware as i take care of every inch of it after every single ride. Thanks, T
 

Big Daddy 72

Custom Street Rod Interiors & Design
hard to diagnose over the internet but any competent shop this should be an easy fix. Not trying to knock you guy but using the good ole process of elimination going through all the parts you should be able to find the culprit pretty easy. Just for sanity sake try another shop.
 

pauly

Active Member
Your master cylinder is probably tilted and the port hole is not submersed in fluid.
I would also put new seal kit and top cover gasket in to fix the leak.

Paul.
 

keverett91507

Active Member
I bought a self bleeder kit from Harbour Freight that works great at getting all the air out with just one person. Was also losing my brake and changes all the brass washers top and bottom and no problem since. Hopefully this helps
 

BWG56

Guru
The leak at the handle bar is either the brake line, cap seal or the piston seal. If its loses pressure over time, rebuild the master cylinder. Are they using Dot-5 fluid?
The caliper is either going to leak or the piston will stick if its that, but your problem is up at the handle bars
 

BadDawg Bill

Well-Known Member
If it were only that simple. However, as I mentioned in my original post this has been going on a long time and this "leak" is new. I think it was overfilled on purpose and this did not work. The leakage is from around the lever/master area which I saw filled to the top. So its not as simple as a leak since its been doing this for a long time. It goes along for a while but always comes back to this problem again. I go for the lever and it just pulls all the way back. They even put new shoes on it. I know it sounds as if it is an obvious problem, but its not. No one has solved it for more than a limited time. One person said that it was due to the placing of the bleeder hole in the cylinder and that the fluid at times would "run" away from it and leave "air". Or something like that, I will go find that invoice and put in here exactly what was said/found by a tech widely believed to be one of the best in this area. T
The Master cylinder and system is a closed system. The reason the calipers work is because of the pressure pushing the fluid through the line. Any tiny leak (whether) it leaks fluid or air will cause failure. A tiny/loose fitting or seal could allow air in but not big enough to push fluid out and if fluid comes out it's a Major problem and leak.

I spent months trying to fix my back brake once and changed everything (all at once) and still had no brake after a few stops. The problem was the T fitting at first but then when I replaced that the line going into it sucked in air and I had the same problem. I replaced the line and still had the problem. I could go on and on but after starting at the master cylinder and making sure it was good/sealed and following everything all the way down the line and trying it after each change I finally got a brake.
 
The Master cylinder and system is a closed system. The reason the calipers work is because of the pressure pushing the fluid through the line. Any tiny leak (whether) it leaks fluid or air will cause failure. A tiny/loose fitting or seal could allow air in but not big enough to push fluid out and if fluid comes out it's a Major problem and leak.

I spent months trying to fix my back brake once and changed everything (all at once) and still had no brake after a few stops. The problem was the T fitting at first but then when I replaced that the line going into it sucked in air and I had the same problem. I replaced the line and still had the problem. I could go on and on but after starting at the master cylinder and making sure it was good/sealed and following everything all the way down the line and trying it after each change I finally got a brake.
Bill, thank you for your reply and explanation, did you ever figure out exactly what the cause was or is it just finally go away after everything was replaced. I cannot quite tell by your post is you were able to finally diagnose the problem or not.

So it seems I should start with a master cylinder rebuild? This does not consist of many parts to replace looking at the kit, but it may be more difficult to do than it looks.

Looking at the replies no one thing stands out. I have been dealing with this for a very long time. Putting on new pads gave me brakes again with a full lever, then it started leaking, it had never leaked before yet I still had the problem. After putting on the new pads getting the fluid in very carefully (I was observing) I made a couple of rides with no problem. I then had a moment where the bike was leaned over very briefly on the opposite side (from the master) it was after this I noticed the leak, not at once but after another ride. I don't see how this had anything to do with it, but I did not notice any leaking until after that. The brakes have not failed but they are as they always do..acting erratic..I may have a full lever or 1/4 lever. In my experience it eventually goes to zero. I have had the brakes bleed and refilled a number of times, it seems like I have had this problem for so long as it varies how long it would work before once again starting the same symptoms. I listed above exactly what the conclusion was. The leak is a few small drops gathering under the cylinder area, but the first two times it leaked it was more than a few drops. I am darn tired of this same thing which cannot seem to be solved and I have had it worked on by three different individuals. I am at a loss. Thank you, Tony
 

BadDawg Bill

Well-Known Member
Bill, thank you for your reply and explanation, did you ever figure out exactly what the cause was or is it just finally go away after everything was replaced. I cannot quite tell by your post is you were able to finally diagnose the problem or not.

So it seems I should start with a master cylinder rebuild? This does not consist of many parts to replace looking at the kit, but it may be more difficult to do than it looks.

Looking at the replies no one thing stands out. I have been dealing with this for a very long time. Putting on new pads gave me brakes again with a full lever, then it started leaking, it had never leaked before yet I still had the problem. After putting on the new pads getting the fluid in very carefully (I was observing) I made a couple of rides with no problem. I then had a moment where the bike was leaned over very briefly on the opposite side (from the master) it was after this I noticed the leak, not at once but after another ride. I don't see how this had anything to do with it, but I did not notice any leaking until after that. The brakes have not failed but they are as they always do..acting erratic..I may have a full lever or 1/4 lever. In my experience it eventually goes to zero. I have had the brakes bleed and refilled a number of times, it seems like I have had this problem for so long as it varies how long it would work before once again starting the same symptoms. I listed above exactly what the conclusion was. The leak is a few small drops gathering under the cylinder area, but the first two times it leaked it was more than a few drops. I am darn tired of this same thing which cannot seem to be solved and I have had it worked on by three different individuals. I am at a loss. Thank you, Tony
I feel your pain. I went for a year without a back brake. I even broke down and took it to a guy who knew more than I did and he couldn't fix it. I'd just rebuild the master and test it out. If you still have the problem replace the line. Do it step by step until it's fixed. I think my problem was the rear line because after I replace that it was fixed. That was the last thing I did. Testing in between fixing/replacing something is the way to go. With so many places for it to suck in air it's hard to pin it down. Buy a vacume brake bleeder around $12 on ebay because that's the only way to insure you got all the air out... Another thing, my friend put in dot4 into his dot 5 master and really screwed everything up. It turned to jelly and he had to replace everything. Make sure that wasn't done to you.

Good luck my friend....
 
The leak at the handle bar is either the brake line, cap seal or the piston seal. If its loses pressure over time, rebuild the master cylinder. Are they using Dot-5 fluid?
The caliper is either going to leak or the piston will stick if its that, but your problem is up at the handle bars
Thank you for your reply. Yes, it loses pressure over time, yes dot 5. Leak is only at the cylinder area and this is the only time it has ever leaked as part of its symptom. It just keeps happening and no one has ever suggested the master cylinder, this problem keeps occurring over and over. Thank you, Tony
 
I feel your pain. I went for a year without a back brake. I even broke down and took it to a guy who knew more than I did and he couldn't fix it. I'd just rebuild the master and test it out. If you still have the problem replace the line. Do it step by step until it's fixed. I think my problem was the rear line because after I replace that it was fixed. That was the last thing I did. Testing in between fixing/replacing something is the way to go. With so many places for it to suck in air it's hard to pin it down. Buy a vacume brake bleeder around $12 on ebay because that's the only way to insure you got all the air out... Another thing, my friend put in dot4 into his dot 5 master and really screwed everything up. It turned to jelly and he had to replace everything. Make sure that wasn't done to you.

Good luck my friend....
Thank a lot Bill, it sounds like good advice but its going to keep me from riding since I don't wrench it myself it will take a while. Since it is my front brake I cannot just do without it. But it seems no answer is obvious. Thanks again for your time. Tony
 
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