Author Topic: Front Won't Build Pressure  (Read 5505 times)

Offline VirginiaJim

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Re: Front Won't Build Pressure
« Reply #60 on: March 26, 2020, 08:26:26 pm »
watched this thread from page one. and refrained from any responses, to allow all the other folks to do so, and find it a bit refreshing, with so little given, just waiting it out.


Rich, if you have any insight into this please do tell.  I'm sure the OP would like to hear just about anything that might fix the situation.
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Offline okrider

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Re: Front Won't Build Pressure
« Reply #61 on: March 27, 2020, 12:56:48 pm »
Loosened the bolts keeping the caliper halves together and retightened, and as expected, no difference.. I don't see any fluids leaking anywhere.
'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 #62 on: March 27, 2020, 01:05:14 pm »
I guess I'm going to assume there's a leak and re-do the rebuild with a new set of seals, and new pistons this time.. unless anyone has any idea. Anything.. Even if you think it's a stupid idea, I want to hear it
'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 #63 on: March 27, 2020, 02:36:21 pm »
I bled the left caliper with the mityvac (not air compressor version), finished the big bottle of brake fluid I had opened yesterday. There's no way I haven't replaced the whole line worth of brake fluid multiple times at this point..

just did a test ride, no real improvements. I was able to lock the front tire a little bit when going fast enough. It does feel like there's air in the lines. Especially at the very beginning of the test ride. The lever was hard and then let go for a very little bit as if an air bubble just burst.

Just to recap, I can build pressure by pumping the lever a couple times and even then it's not enough for an emergency brake situation. The pressure is gone within 10 seconds and the lever comes in much more. It's not like it's a dead lever (I can easily pull it to the handlebar) but I can pull it to the handlebar with enough pressure. Definitely worse than before I split these brakes apart.

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

Offline Bob Skinner

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Re: Front Won't Build Pressure
« Reply #64 on: March 27, 2020, 05:53:56 pm »
This is probably a stupid idea, but here's what I would try.
Raise the front wheel off the ground where it's free to spin. Pump the brake lever to build as much pressure as you can and keeping the lever pulled - tie the lever in the pulled position. This will put as much pressure as you can on the calipers. Verify that you can't spin the front tire with just using one hand. If you can spin the front tire with just one hand notice how much drag there is.
Leave the bike like this for 8 hours or longer.
Now try spinning the front tire again and notice if there is any change. (wheel spins the same - same drag, it spins free or can't spin at all).
This will tell you if there is a system leak if there is a change.
If the front tire spins free I suspect the master cylinder is leaking on you. Next I would try pinching the  master cylinder brake line closed with a clamp or pair of vice grips installed at a 45 degree angle to clamp off the brake line. Now the brake lever pull should only move slightly and be very solid. This will tell you that the master cylinder is working.
IF YOU DO PINCH OR CLAMP THE BRAKE LINE BE SURE TO REPLACE IT WITH A NEW LINE.

hope this helps.


Offline okrider

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Re: Front Won't Build Pressure
« Reply #65 on: March 27, 2020, 06:32:26 pm »
I have been keeping the lever pulled in with a ziptie for the past many nights.. Sometimes if I ziptie it, and then get back to it couple hours later, it'll have no pressure, but usually it's about as firm as I left it. Haven't noticed a pattern. Left in on the side stand with a ziptie in tonight, if there's no air that comes out of the calipers tomorrow, I'm going to be convinced the calipers don't have any air (I'm already pretty freaking convinced)
'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 #66 on: March 28, 2020, 07:51:50 am »
At this point, there is nothing 'stupid' in anything you are doing including redoing the seals again.  I would do the same thing.
"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 #67 on: March 28, 2020, 08:09:06 am »
I think this time I'll get new pistons as well, as I have scratched a couple pistons a little bit when pulling them out, I used sandpaper to smooth them out, and they aren't far enough down to hurt the seals but you never know I guess. If there is a leak, I don't see it.. after multiple inspections
'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 #68 on: March 28, 2020, 12:52:23 pm »
No air.. I inspected the pistons and all that and I can't tell where/if a leak is. I got in touch with Murph to order another brake rebuild kit, this time with pistons. Saw this kit on eBay for $35 (https://www.ebay.com/itm/Kawasaki-Concours-1400-2008-2016-Front-Brake-Caliper-Rebuild-Kit-ZG1400/382161955386) but I don't know about getting oil seals that aren't OEM. Doubt these are OEM...
'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 #69 on: March 28, 2020, 01:06:17 pm »
I would trust Murph's products over anything on ebay.
"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 gPink

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Re: Front Won't Build Pressure
« Reply #70 on: March 28, 2020, 01:08:49 pm »
How long before you rebuild the master cylinder? ...or did I miss that?
Thank God for good men willing to do extreme violence.

Offline VirginiaJim

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Re: Front Won't Build Pressure
« Reply #71 on: March 28, 2020, 01:12:11 pm »
I don't think it's going to make any difference personally but that's not up to me.  If it was fine before, I don't know why you'd want to do it now.  But then again, desperate times.....
"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 #72 on: March 28, 2020, 02:47:20 pm »
I have not rebuilt the master yet. I don't want to introduce more air into the system if I don't need to, and with the amount of brake fluid I've gone through, I don't think there's any air left anywhere, I do believe there's some sort of a leak I can't figure out yet. I think at this point I'm going to get a used set of calipers and try to throw that on, see what happens
'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 #73 on: March 28, 2020, 04:44:57 pm »
Just ordered a used set of calipers from Florida, hopefully they'll come in soon
'11 Black: Russel Day-Long, Mountain Runner, cage w/ highway pegs, 2Bros Slip-on, Helibars Horizon

Offline Rubber_Snake

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Re: Front Won't Build Pressure
« Reply #74 on: March 28, 2020, 08:17:43 pm »
If there is a leak somewhere, shouldn’t there be fluid present?  I’m not a mechanic, and I wish I had the answer for you, but if there is a leak, there definitely should be an area where the fluid is escaping from.  Does the fluid level in the MC drop over time?  I know you just ordered a used set of calipers, but if the originals aren’t leaking, then they shouldn’t be the problem.  Just my 2 cents. (which has an actual value of 1.5)

P.S.  I keep hoping that every time I see an update to this thread, it is you declaring your success, so don’t give up!  We’re rooting for ya!
2009 GTR 1400 ABS, 48k miles, AMSOIL synthetic 10W-40 (since new), AMSOIL synthetic 75W-90 final drive (since new). Helibar Horizons, Oxford heated grips, V-Stream windscreen, Mountain Runner Flash, Brian’s low fuel eliminator farkle, ST2 smart brake module and smart turn system, Two Brothers Black Series M5 w/P1X decibel killer.