Author Topic: Front Won't Build Pressure  (Read 10316 times)

Offline tweeter55

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Re: Front Won't Build Pressure
« Reply #140 on: April 27, 2020, 07:12:02 PM »
Just grasping at straws here.
When you’re rebuilding/assembling is it possible you might be using an assembly lubricant that is detrimental to the rubber parts?
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #141 on: April 27, 2020, 07:24:57 PM »
Not using any lubricant besides brake fluid..

The weird thing is, if I put a ziptie on the lever after bleeding, the lever feels the same usually the next day. But if I ride the bike, come home and then put a ziptie, then the lever has no pressure whatsoever within a couple hours, which made me think of an air bubble expanding as the bike warms up, but then shrinks as it cools down, making the pressure go away..
« Last Edit: April 28, 2020, 10:53:27 AM by okrider »
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Offline just gone

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Re: Front Won't Build Pressure
« Reply #142 on: April 28, 2020, 11:00:01 AM »
So let me see if I understand this. You've rebuilt and or replaced a whole bunch of stuff, performed several bleeds and when you finish working on it (without riding it) it will hold pressure overnight.
However when you test it after riding it then it won't hold pressure for more than a few hours at most?

If that's true then I would suspect the ABS pump/linked brakes system is where the problem is, as the unit only activates when you ride it faster than 3 mph. Right?

I get so paranoid about screwing up the paint that I'm a nervous wreck whenever I bleed the bike, I've got plastic coverings and rags everywhere. I can't imagine
doing all that you have done so far. How many gallons of brake fluid have you gone through?

Best wishes with this, keeping an eye on this thread for sure.

Offline okrider

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Re: Front Won't Build Pressure
« Reply #143 on: April 28, 2020, 11:05:48 AM »
This morning, the lever was ziptied shut after my test ride yesterday, and as expected, had no lever pressure, I could easily move the bike back and forth while the lever was ziptied. So I decided I'm going to try to do a reverse bleed to push whatever's upwards. Pulled the ziptie off, proceeded to made a mess after pushing a little bit of fluid in as the hose just came off the caliper and brake fluid everywhere. Lots of cursing.. Then I bled normally a little bit, thinking I let air into the caliper while the reverse bleed injector was disconnected. Then I bled the master because why not.

Got a big bubble out, not sure where it came from, but the lever felt pretty good after that, so I just did another test ride and put the ziptie back on. Going to see how it is in a couple hours, try to bleed the master first, followed by reverse bleed followed by bleed the master again to see if I get anything.

I've also ordered a used left caliper as the one I received was faulty and was leaking from the banjo bolt. So my thoughts are it's either air trapped in the ABS unit that I'm having a hard time getting out, or the caliper is letting air in through the new seals.. Even though I took the caliper apart and inspected after I was having issues initially and the o-rings looked just fine.



'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline okrider

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Re: Front Won't Build Pressure
« Reply #144 on: April 28, 2020, 11:14:45 AM »
If that's true then I would suspect the ABS pump/linked brakes system is where the problem is, as the unit only activates when you ride it faster than 3 mph. Right?

Where exactly is the ABS module so I can check it for leaks? I doubt that's the cause but at this point, I have no idea
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Offline Freddy

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Re: Front Won't Build Pressure
« Reply #145 on: April 28, 2020, 06:06:16 PM »
The ABS unit is behind the battery, on the left side of the bike but you must remove the fuel tank and a cover to see it.  If it is leaking, which would be a first, you'd see fluid under the centre of the bike.

Try NOT tying the lever and see what happens. 
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #146 on: April 29, 2020, 07:37:06 AM »
Try NOT tying the lever and see what happens.

 ;D That's actually a great idea. I don't think I've tried that. So I took the bike for the same test ride this morning, lots of braking, brought it home and parked. Then I took my other bike that has linked brakes (S1000RR) and did the same test ride, parked and put the ziptie on. My thought process is if the BMW is also losing pressure, that's just something linked brakes do.. if not, Kawi is still sick.
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline okrider

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Re: Front Won't Build Pressure
« Reply #147 on: April 29, 2020, 11:09:01 AM »
ok I just checked the bike, and the brake pressure is fine on the Concours after leaving it without a ziptie, the BMW also had pressure after sitting with the ziptie though. I'm wondering if someone can do me a huge favor and put a ziptie on their bike with linked brakes after a quick ride.
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Offline MAN OF BLUES

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Re: Front Won't Build Pressure
« Reply #148 on: April 29, 2020, 03:16:19 PM »
not me... system was never designed for that.  I don't have linked brakes anyways, on my '08, just ABS.
I think you may have found the "cure" was to not over stress the actual system.

Hope this was the case, and you now can enjoy riding time.

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Offline Freddy

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Re: Front Won't Build Pressure
« Reply #149 on: April 29, 2020, 04:11:21 PM »
I'm with MOB.   :chugbeer:

I think someone said a page or 2 back that it's an old wives tale.   :deadhorse:
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #150 on: April 29, 2020, 04:24:04 PM »
what's the old wives tale? the ziptie trick? My goal here's not to bleed with the ziptie, it's to see if pressure remains so I can see if I have a potential leak
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Offline MAN OF BLUES

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Re: Front Won't Build Pressure
« Reply #151 on: April 29, 2020, 05:35:21 PM »
I could pretty much guarantee, If I sat in my truck, and pressed the brake pedal "hard" for a 24 hour period.. it would end up on the floor.  That "process" was con-notated over years, to be done for a short period of time (a couple hours), to force air bubbles to congregate into one big bubble, to be bled from the system. Not as a continuous and repeated long period method for "ridding" anything, just a short period, and done.  A simple "method" has been construed as a well documented issue in this case, where over use, and a lack of caution, turns into something that does not work.
If you were not getting air bubbles after all that tying of the lever, it does show you just applied enough pressure, to overcome the seal's capacity for sealing the fluid pressurized internally, nothing more.

46 YEARS OF KAW.....  47 years of DEVO..

Offline Freddy

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Re: Front Won't Build Pressure
« Reply #152 on: April 30, 2020, 06:47:00 AM »
 :goodpost:
The best substitute for brains is .............what?

Offline okrider

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Re: Front Won't Build Pressure
« Reply #153 on: April 30, 2020, 06:59:31 AM »
OK, so since it can keep pressure overnight when cold and the brakes feel decent overall, I have decided to let go of this problem and ride the sucker. I'm going to replace the fluid one last time as I've been using old (month old) brake fluid to stop having to buy a $10 bottle every other day. If it is in fact leaking, I will know soon as the fluid level will go down, and I'll start feeling air bubbles in the system
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #154 on: April 30, 2020, 03:22:24 PM »
Just did another ride, longer this time. Brake lever pressure is pretty steady, but I think my pads are soaked with brake fluid, the bite isn't as good as I remember. Anyone know if I can somehow rid the pads of brake fluid somehow besides spraying brake cleaner?
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Offline Freddy

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Re: Front Won't Build Pressure
« Reply #155 on: April 30, 2020, 03:53:45 PM »
Water is best if on pads, then spray.  Good luck with it.
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Offline VirginiaJim

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Re: Front Won't Build Pressure
« Reply #156 on: April 30, 2020, 05:02:55 PM »
Did I miss something here?  The pads are soaked with brake fluid?  That can't be right.  If the pads are contaminated you can try brake clean spray but depending on how much contamination you many need to replace them.

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Offline MAN OF BLUES

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Re: Front Won't Build Pressure
« Reply #157 on: April 30, 2020, 05:48:30 PM »
water and brake fluid are nemesis'.. just don't ever have water, near anything with brake fluid, the results will be severe corrosion, .. not good..
use the stuff that this needs..



saturate the removed pads, spray a bunch, and lay them lining side down on a multi layered towel, and repeat about 4 or five times, until the pads give up no more contamination.. then lightly scrub them on a flat surface, over a piece of 120 grit sand paper, and re-spray.. to remove the dust.


now, are we now seeing leaky seals in the calipers? this story seems never ending, I really wish you were near me, so I could fix the problems, and you could go ride..

46 YEARS OF KAW.....  47 years of DEVO..

Offline Freddy

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Re: Front Won't Build Pressure
« Reply #158 on: May 01, 2020, 01:44:00 AM »
'..........and you coulld go ride' and we could have some peace.    :rotflmao:
The best substitute for brains is .............what?

Offline okrider

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Re: Front Won't Build Pressure
« Reply #159 on: May 01, 2020, 05:57:18 AM »
I think the pads are contaminated because of the constant removal/installation of banjo bolts, bleeder valves, and hose coming off while trying to reverse bleed, spraying brake fluid everywhere, not because of a constant seal leak. And to answer your question, no I don't see any seal leaks
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon