Author Topic: Front Won't Build Pressure  (Read 2097 times)

Offline okrider

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Front Won't Build Pressure
« on: March 15, 2020, 07:41:27 pm »
Hey all, kinda losing my mind here. Help would be appreciated. I rebuilt the calipers today (new seals), and now I'm having trouble getting fluid to enter the calipers and getting the air out.

I have it so if I pump the brakes, the lever firms up, but if I let go for about 10 seconds, it goes all the way to the handlebar.

I have speed bleeders, the fluid that comes out of them is clear without bubbles. I've tried unbolting the calipers and compressing the pistons with the bleeder open which let some air out, but after doing that a couple times, now all I get is just brake fluid again.

I assume there's air trapped somewhere in the caliper. No idea how to get it out. Going to ziptie the lever in overnight to see if it gets any better. My next idea is to install the old bleeders and force fluid with a syringe. Been at this for way longer than I intended so I'm going to go to bed now. Hoping you guys can chime in and give me some ideas.  Thanks!

« Last Edit: March 15, 2020, 08:12:37 pm by okrider »
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline Boomer

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Re: Front Won't Build Pressure
« Reply #1 on: March 16, 2020, 02:40:23 am »
Sounds more like you have air trapped in the lines.
Have you bled the system at the master cylinder bleed nipple as well?

If you let the system drain dry, then refilling it without a well sealed vacuum/pressure fed system is a PITA.
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Offline VirginiaJim

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Re: Front Won't Build Pressure
« Reply #2 on: March 16, 2020, 06:26:19 am »
Also make sure that you don't double up on the sealing washers...don't ask me how I know this.
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #3 on: March 16, 2020, 06:32:01 am »
While the caliper was off, I used a plastic caulk cap to prevent the line from leaking all the fluid, reservoir was never empty. The lines were still leaking when I put them back on the caliper so I don't think the lines went dry. I've bled it at the master as well, very little air there.. (I assume some air made its way up)

Did not double up on the washers, 4 came out (total), 4 went back on.

I don't think there was air in the lines.
'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 #4 on: March 16, 2020, 09:01:37 am »
Just tried the syringe method couldn't pump any fluid into it. Back to square 1.
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline VirginiaJim

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Re: Front Won't Build Pressure
« Reply #5 on: March 16, 2020, 11:21:57 am »
You have bled the bleeder valve on the master cylinder, correct?


I broke my calipers apart and redid the seals and didn't have any issues like you're having but my bike was an 08.
"LOCTITE®"  The original thread locker...  #11  2020 Indian Roadmaster, ABS, Cruise control, heated grips and seats 46 Monitoring with cutting edge technology U.N.I.T is Back! 2008 C14 Moved on to a new home, 2016 RM traded in.

Offline okrider

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Re: Front Won't Build Pressure
« Reply #6 on: March 16, 2020, 11:35:56 am »
Yes I have bled at every nipple possible. I have horizon helibars and have longer lines because of that which has its own nipple, bled everything. Not sure what to try anymore
'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 #7 on: March 16, 2020, 11:43:09 am »
I broke my calipers apart and redid the seals and didn't have any issues like you're having but my bike was an 08.

Did you prime the calipers somehow? before installing?
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline VirginiaJim

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Re: Front Won't Build Pressure
« Reply #8 on: March 16, 2020, 02:01:10 pm »
It was awhile back but if I did anything I let them gravity drain first before going through the bleeding process.
"LOCTITE®"  The original thread locker...  #11  2020 Indian Roadmaster, ABS, Cruise control, heated grips and seats 46 Monitoring with cutting edge technology U.N.I.T is Back! 2008 C14 Moved on to a new home, 2016 RM traded in.

Offline okrider

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Re: Front Won't Build Pressure
« Reply #9 on: March 16, 2020, 04:21:16 pm »
It was awhile back but if I did anything I let them gravity drain first before going through the bleeding process.

How does one gravity drain calipers? I thought that was for the brake lines. My brake lines were already leaking when I reinstalled them.

'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 #10 on: March 16, 2020, 04:22:32 pm »
I think I'm going to try riding it like this, see if it gets any better. There's also an annoying amount of air in the clutch lines which I can't seem to get out. Nothing comes out of the bottom, by the slave, master seems to have a constant stream of air going into it
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline Freddy

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Re: Front Won't Build Pressure
« Reply #11 on: March 16, 2020, 05:45:27 pm »
Get yourself a reverse bleeding kit and put it to use. 
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Offline zrx mitch

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Re: Front Won't Build Pressure
« Reply #12 on: March 16, 2020, 07:06:18 pm »
Just tried the syringe method couldn't pump any fluid into it. Back to square 1.


Did you remove the speedbleeders?
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #13 on: March 16, 2020, 08:40:31 pm »
yes I installed the oem bleeders to try the syringe. But I didn't have the lever pulled in. I assume that has to do with it, as you can't force fluid into a full system. Going to try it again tomorrow I think..
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline Freddy

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Re: Front Won't Build Pressure
« Reply #14 on: March 16, 2020, 11:23:24 pm »
If you pull the lever (even a fraction) that will close off the internal ports in the m/cyl, preventing any reverse fluid flow.
The best substitute for brains is .............what?