Kawasaki Concours Forum

The C-14, aka Kawasaki Concours-14, the new one :) => The Bike - C14/GTR 1400 => Topic started by: okrider on March 15, 2020, 07:41:27 pm

Title: Front Won't Build Pressure
Post by: okrider 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!

Title: Re: Front Won't Build Pressure
Post by: Boomer 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.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 16, 2020, 09:01:37 am
Just tried the syringe method couldn't pump any fluid into it. Back to square 1.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: okrider 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?
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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.

Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: Freddy on March 16, 2020, 05:45:27 pm
Get yourself a reverse bleeding kit and put it to use. 
Title: Re: Front Won't Build Pressure
Post by: zrx mitch 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?
Title: Re: Front Won't Build Pressure
Post by: okrider 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..
Title: Re: Front Won't Build Pressure
Post by: Freddy 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.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 17, 2020, 05:48:48 am
I would expect it to be the exact opposite. That the fluid won't have anywhere to go if the lever is not pulled as the opening to the reservoir is closed.
Title: Re: Front Won't Build Pressure
Post by: Freddy on March 17, 2020, 08:04:44 am
You need to study hydraulic brake circuits 101.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 17, 2020, 08:07:56 am
I'll go sign up for that in my local community college
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 17, 2020, 11:09:09 am
I put everything back together and then just opened the bleeder on the caliper and let it flow from it.  You don't have to leave the caliper on the bike for this to work.  It shouldn't take that long for fluid to come out of the bleeder.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 17, 2020, 11:38:02 am
I'll try this tonight if nothing else works. Going to try reverse bleeding again today, ziptieing the hose so it doesn't come out and make a mess.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 17, 2020, 03:24:19 pm
Just did reverse bleed and went for a quick test ride. No difference. Very little front brake. Tried getting ABS to kick in, couldn't even do that.

I think I'm going to take a break, and get back to this tomorrow or next day and take the calipers apart again and re-do the whole thing, but I won't replace the seals this time. Just take apart and inspect
Title: Re: Front Won't Build Pressure
Post by: gPink on March 17, 2020, 03:55:27 pm
The brakes are linked? What happens when you activate the rear only?
Title: Re: Front Won't Build Pressure
Post by: okrider on March 17, 2020, 06:22:04 pm
yes, they're linked. The rear seems to work fine, like before.
Title: Re: Front Won't Build Pressure
Post by: gPink on March 17, 2020, 06:28:08 pm
yes, they're linked. The rear seems to work fine, like before.
Does engaging the rear activate the front?
Title: Re: Front Won't Build Pressure
Post by: Freddy on March 17, 2020, 06:38:24 pm
                     Going to try reverse bleeding again today, ziptieing the hose so it doesn't come out and make a mess.

If you're reverse bleeding the circuit why do you need to do this?   Secondly, what are you using to reverse bleed it with?  Thirdly, exactly what procedure, step by step, are you following?
Title: Re: Front Won't Build Pressure
Post by: okrider on March 18, 2020, 07:28:18 am
If you're reverse bleeding the circuit why do you need to do this?   Secondly, what are you using to reverse bleed it with?  Thirdly, exactly what procedure, step by step, are you following?

I got a big syringe I'm using to reverse bleed, the hose I attach on the syringe slips off and makes a mess, hence the ziptie.
Title: Re: Front Won't Build Pressure
Post by: Freddy on March 18, 2020, 05:52:31 pm
 :thumbs:  That should do it.  Any improvement?
Title: Re: Front Won't Build Pressure
Post by: okrider on March 20, 2020, 05:07:01 pm
No, it's still the same as before. I haven't had a chance to touch the bike since the test ride. I did notice the next day that the lever was empty for 2 pulls. no resistance whatsoever. Then I went back to check the day after and it had the same amount of brakes as before where it's nowhere near enough, but you can't super easily touch the lever to the bar. Going to try to spend more time on it this weekend
Title: Re: Front Won't Build Pressure
Post by: zrx mitch on March 20, 2020, 06:19:51 pm
I would be inspecting the caliper piston fluid and dust seals for proper installation.
Title: Re: Front Won't Build Pressure
Post by: Y0ssarian on March 21, 2020, 03:08:03 am
If the bike has linked brakes don't you need to bleed the system at both ends using both the front lever and the brake pedal?
Title: Re: Front Won't Build Pressure
Post by: Michelle on March 21, 2020, 04:44:59 am
If the bike has linked brakes don't you need to bleed the system at both ends using both the front lever and the brake pedal?

No. There is no physical link. It is done by the computer manipulating the pressure in the abs pump.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 21, 2020, 06:42:33 am
He had brakes before he cracked the calipers.  We don't know the reason to replace the seals in them other than just because.  Two possibilities I see are the calipers and possibly the way the linked brakes work hydraulically.  I cracked open both my fronts and didn't have this much issue with getting the system bled other than putting two washers together on one side.  Still have to get that fixed for my friend who bought my bike.
Someone with a manual, is the brake bleeding procedure different on these bikes?

I have a hard time thinking this is something other than what was touched to begin with.

Man, I'd love to be closer to the OP to see what's going on with this and troubleshoot the issue.  What a crazy interesting issue!
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 21, 2020, 08:21:37 am
New washers, right?
Title: Re: Front Won't Build Pressure
Post by: okrider on March 22, 2020, 07:09:25 am
New washers, new seals, old pistons. Going to be taking it apart again and inspecting my work. I agree with zrx mitch that it must be something I've done wrong. I just don't know what it is. First time rebuilding brakes, I'll post if I can find what's wrong.

What's the suggested way to bleed calipers to ensure no air is trapped in the caliper after rebuilding it?

Back when I was first bleeding, I could get air bubbles out by compressing the caliper with the bleeder nipple open, which leads me to believe this whole thing's happening because there's still air there
Title: Re: Front Won't Build Pressure
Post by: okrider on March 24, 2020, 10:37:04 am
Took the left side apart yesterday, inspected everything and reinstalled, didn't see anything out of the ordinary besides some shaved metal, I think I misplaced the pistons, I figured they'd be identical but maybe not? Because some piston grooves had some markings on the middle.

Anyways, cleaned everything up, put it back together, it gravity bled by the time I put the bleeder in, bled the brakes for quite a while and it feels a little better than before, going to do the right side too, hoping I get all the air out this time
Title: Re: Front Won't Build Pressure
Post by: okrider on March 24, 2020, 02:57:28 pm
Just redid the right side as well, didn't see anything wrong with it, put it together. Did the bleeds, got a bunch of air out, now I have clear fluid coming out of all the orifices, and I still have super spongy brakes, they build pressure if I pump 3 times but lasts about 3-4 seconds and it's back to the handlebar after that.

Does anyone have any ideas? I'm quite frustrated and don't know what to do anymore..
Title: Re: Front Won't Build Pressure
Post by: Daytona_Mike on March 24, 2020, 03:37:12 pm
Just redid the right side as well, didn't see anything wrong with it, put it together. Did the bleeds, got a bunch of air out, now I have clear fluid coming out of all the orifices, and I still have super spongy brakes, they build pressure if I pump 3 times but lasts about 3-4 seconds and it's back to the handlebar after that.

Does anyone have any ideas? I'm quite frustrated and don't know what to do anymore..
Well, this is a long shot  but maybe ..this could be your issue.  I have seen on another bike where a caliper was incorrectly installed The Caliper could not center itself on the slide pins.  So when you applied the brakes it took two or three pumps and the brakes would work fine but then a few seconds later - no brakes- you have to pump 3 times again. What happened was the piston on the stuck caliper  pushed on one side only  of the rotor...the rotor would bend over slightly  like a spring... then the rotor would push  / spring back the piston back in again to create a large gap.... so  you had to pump the lever several times again.   Is it possible this is what yours is doing? The other front  caliper could center just fine. The   other side  could  not center which  caused the problem.


.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 24, 2020, 03:48:09 pm
Hmm, I guess I'll observe the pistons squeeze the rotor tomorrow. The reason I took the calipers apart is because my brakes were dragging. I don't know they're still dragging as the bike's still on the lift.

I also don't tighten the caliper mount bolts until I squeeze the brake lever and have the caliper center itself

Title: Re: Front Won't Build Pressure
Post by: Daytona_Mike on March 25, 2020, 12:59:41 pm

I also don't tighten the caliper mount bolts until I squeeze the brake lever and have the caliper center itself
I never heard of that procedure. Is it in a book or service manual?
I think the calipers may cock  and bind  if you do that.   Tighten the bolts to spec first unless you know  otherwise and can show me please.

Interesting that you had a bind at first.  You may still have the original problem. Before installing the pads... did you verify the caliper can center and move back and forth on the slides. One caliper may still be bound up.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 25, 2020, 02:35:41 pm
here's why I squeeze the brakes first before tightening the bolts. https://youtu.be/C26ww0dsMTI?t=296

so after bleeding everything including myself (pinched my finger), I removed the calipers, pushed the pistons in and hung them sideways using a bungee cord to force any air that might be stuck somewhere/anywhere up towards the bleeder, going to try bleeding again tonight to see if I get any bubbles
Title: Re: Front Won't Build Pressure
Post by: Daytona_Mike on March 25, 2020, 03:35:53 pm
Oh shyte  .. you are correct. C14 front brakes are  not self centering with slides.
 I learned something today. Thank You.  I was thinking of my old C10 and my dirt bikes... all self centering.                                                     
                            C14 are radial -opposing piston- fixed caliper brakes.  My bad..   On my KTM's you spin the wheel and hit the brake to center the wheel before tightening the pinch bolts.    Now I am back to wondering what your issue is?  One side (2 of the 4 pistons)  of the caliper pushing harder than the other side?    Now you have me watching his videos.  Is there a chance you need a master rebuild? How old is your bike?


Title: Re: Front Won't Build Pressure
Post by: Michelle on March 25, 2020, 06:10:58 pm
Left field question. Does it have the stock brake lever?

Also remember that on a linked brake bike the line goes from the master back under the tank to the ABS unit, then two lines come back under the tank, all the way to each front caliper. That's a lot of line to hide air bubbles in.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 25, 2020, 07:42:11 pm
I don't think my master needs a rebuild as it was working fine before I tore the calipers apart. My bike's a 2011 with 43k miles. It is a very long system, I'm aware, I just don't know what to do to completely flush the system. I think I'll buy some more brake fluid tomorrow and do a non stop flush for about 15 minutes, see if I get anything.

I tried hanging the calipers sideways today to see if I can get any air out that might've been stuck inside the caliper, I got nothing, going to leave it hanging upside down overnight, with the lever pulled, see if it's better by morning.

It does have the stock lever. Why?

There's no bleed nipples by the abs unit right? That would've helped as I could scratch it off the list. Of course the ABS unit having upward facing hoses doesn't help the situation, some chance I got a bubble in the stupid ABS unit as it's a high point.

Title: Re: Front Won't Build Pressure
Post by: Michelle on March 26, 2020, 01:04:35 am
Some similar problems have been traced back to aftermarket levers. So we know it isn't that.
I use a vacuum pump to suck the fluid through, rather than push. Makes life a whole lot easier and saves swear words for when I really need them.  ;)

https://www.harborfreight.com/Brake-Bleeder-and-Vacuum-Pump-Kit-63391.html (https://www.harborfreight.com/Brake-Bleeder-and-Vacuum-Pump-Kit-63391.html)

No, there are no bleeders on the abs unit. One by the master and one on each caliper.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 26, 2020, 05:56:07 am
I have a vacuum pump but I haven't been using it for long enough at a time to move fluid through the entire system, I simply didn't think there'll be air trapped in the lines, and I've been trying to bleed the calipers this whole time, I'm going to try that today. Going to attach the fluid pump to the speed bleeders and pump the brakes like a mad man, see if I get anything out. Fingers crossed..
Title: Re: Front Won't Build Pressure
Post by: Michelle on March 26, 2020, 06:18:30 am
Get a different colour fluid and keep pumping (or sucking) until it comes through.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 26, 2020, 06:48:02 am
This is getting into the realm of a Haroldo thread...Excellent.  I wonder if I can designate that through the software and tag the thread?  I could create a new board just for those types of threads.  We just don't get them often enough.



Title: Re: Front Won't Build Pressure
Post by: Freddy on March 26, 2020, 06:50:33 am
 :yikes:
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 26, 2020, 07:04:06 am
Nothing wrong with that but it's basically a thread where someone does some maintenance (routine or otherwise) and it goes quite sideways and we all chip in to virtually work on it. 
Title: Re: Front Won't Build Pressure
Post by: okrider on March 26, 2020, 11:24:13 am
I just pushed half a big bottle of fluid through the system. No improvement. I'm so frustrated with this..
Title: Re: Front Won't Build Pressure
Post by: MtnRider on March 26, 2020, 12:32:33 pm
Back to Daytona Mike's earlier question. Maybe take the master cylinder apart and clean. Maybe a bit of "stuff" is stuck in there letting fluid bleed back to the reservoir? I'm no brake expert so asking others what they think on this.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 26, 2020, 01:24:11 pm
Personally I would be leery of touching anything else but the calipers themselves.  You could introduce more issues unrelated to the original issue. 


It's been awhile since I put seals in my calipers but do they have to have a specific orientation?  Some seals have a chamfered set in they're not exactly square and they need to be put in the cylinders correctly or they won't work/seal right.  Only way to tell is to feel the seals in the cylinders and see if there's a lip and orient the new seals the same way.


I'm thinking if there is a right way, you should feel the lip on the top side of the seal.


My issue that lasted years was a shudder in the front brakes.  I replaced everything, sometimes twice.  One piston wasn't working right and once I replaced the seals everything was fine except I now have to replace the washer on the left side as I put two of them on the same side.


http://youtu.be/C26ww0dsMTI (http://youtu.be/C26ww0dsMTI)
Title: Re: Front Won't Build Pressure
Post by: MtnRider on March 26, 2020, 01:44:28 pm
Thanks, Jim. Probably right.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 26, 2020, 02:06:24 pm
This is the same video I referenced earlier, the seals don't have a specific orientation as far as I could tell, I definitely ran my finger over them and looked at the new ones for any uneven surfaces but nothing, they seem to go either way.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 26, 2020, 02:32:08 pm
Well, that rules that out..  Probably square cut seals.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 26, 2020, 04:05:29 pm
I did notice that the caliper halves don't come together as flush as they can, going to loosen the bolts and try to see if I can get it to be more flush. I don't think that'll change anything, but I'm grasping at straws here
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 26, 2020, 04:42:18 pm
You replaced the little o-rings sealing the halves, right?  Where did you get the parts for the rebuild?
Title: Re: Front Won't Build Pressure
Post by: okrider on March 26, 2020, 05:47:49 pm
yeah, from Murph
Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES on March 26, 2020, 06:28:20 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.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 26, 2020, 07:19:28 pm
do you mean you're waiting it out, aka you know why this is happening? Because I would really like to stop suffering and start riding  ;D
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: okrider 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.

Title: Re: Front Won't Build Pressure
Post by: Bob Skinner 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.

Title: Re: Front Won't Build Pressure
Post by: okrider 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)
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: okrider 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 (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...
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 28, 2020, 01:06:17 pm
I would trust Murph's products over anything on ebay.
Title: Re: Front Won't Build Pressure
Post by: gPink on March 28, 2020, 01:08:49 pm
How long before you rebuild the master cylinder? ...or did I miss that?
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.....
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: okrider on March 28, 2020, 04:44:57 pm
Just ordered a used set of calipers from Florida, hopefully they'll come in soon
Title: Re: Front Won't Build Pressure
Post by: Rubber_Snake 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!
Title: Re: Front Won't Build Pressure
Post by: okrider on March 29, 2020, 05:57:34 am
Thanks for the support, I've been bleeding so much fluid, cleaning with brake cleaner etc, that while I don't see an active leak, there's so much stains from all the fluids that have been on the caliper over the past couple weeks.
Title: Re: Front Won't Build Pressure
Post by: connie_rider on March 29, 2020, 08:23:56 am
Is there a way you could disconnect and block the lines to each caliper?
If so, might help you isolate where the problem is.

I think the left caliper is attached to the rear (?).
Possibly you have a problem in the Link system?

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: Michelle on March 29, 2020, 07:03:37 pm
There is no link. It is just the computer adding pressure to the other half of the system.

Title: Re: Front Won't Build Pressure
Post by: okrider on March 29, 2020, 08:26:12 pm
There is no link. It is just the computer adding pressure to the other half of the system.

That's what I thought but I wasn't 100% so I didn't say anything.

Ok so after talking to Ari Henning (the guy who made the motorcycle magazine video linked above), I decided to give reverse bleeding another shot. While reverse bleeding the left caliper, I heard (and later saw) some bubbles rise into the master and I was so so happy. But at the end, lever feels the same.. no improvement whatsoever. I may give reverse bleed another shot before

The new used calipers are still on the way, should be here Thursday. I may give reverse bleed another shot before they arrive..
Title: Re: Front Won't Build Pressure
Post by: maxtog on March 29, 2020, 08:59:13 pm
There is no link. It is just the computer adding pressure to the other half of the system.

Plus, Gen 1 don't have linked brakes, anyway.
Title: Re: Front Won't Build Pressure
Post by: okrider on March 29, 2020, 09:02:54 pm
Plus, Gen 1 don't have linked brakes, anyway.

My bike is technically a Gen2? It's a 2011 with linked brakes
Title: Re: Front Won't Build Pressure
Post by: Michelle on March 30, 2020, 03:05:08 am
Plus, Gen 1 don't have linked brakes, anyway.

True. But nobody has a gen 1 like my one.  ;)
Title: Re: Front Won't Build Pressure
Post by: maxtog on March 30, 2020, 03:58:48 pm
My bike is technically a Gen2? It's a 2011 with linked brakes

Yep

Sorry, I got you mixed up with op!  (Not sure how, but it happens)
Title: Re: Front Won't Build Pressure
Post by: connie_rider on March 31, 2020, 09:39:02 am
Okrider, if your still getting air out of the system {after all the bleeding you've done}, I'd have to suspect the master Cylinder.

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: okrider on March 31, 2020, 10:20:05 am
So the way I'm doing the reverse bleeding is by filling the syringe from the master reservoir. I didn't get this burst of air during the first but during the second syringe full, which made me think it had to do with the lines going to the ABS pump. I think air keeps getting trapped in a high point.

But maybe it is the master cylinder, I don't know.. It makes no sense why it would fail all of a sudden as I'm rebuilding the calipers as it was working fine before..
Title: Re: Front Won't Build Pressure
Post by: okrider on March 31, 2020, 10:35:20 am
I actually won't be too upset if it is the master cylinder that's faulty. Better it be broken than me finding out I butchered the caliper job somehow and failing to figure out how..

Just ordered a master cylinder rebuild kit. I'm quite deep into this project at this point, might as well rebuild that too so I don't have to think about it again..
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on March 31, 2020, 11:22:44 am
That's the spirit!
Title: Re: Front Won't Build Pressure
Post by: okrider on April 04, 2020, 05:10:37 pm
Here's the update:
After reading connie_rider's suggestion that it might be the master, I figured I'd give that a shot so I ordered a kit from Murph..

It arrived a couple days later and I took the master apart to find that the replacement kit I received looks pretty different compared to what came out. Quick email to Murph and turns out I bought the rebuild kit for the C10. So I cleaned everything and put it back together and bled it..

And that did it. I wouldn't say the brakes are as good as they can be, but at least they are consistent. I'm going to bleed them once more tomorrow. I think the reason brakes aren't biting as good right now is because I misplaced a couple pads and they need to re-bed.

But I can't complain. It's consistent and that's all I could ask for. I even left it with a ziptie overnight, and it felt the exact same today. So I guess what must've happened is I somehow got air trapped in the master cylinder..
Title: Re: Front Won't Build Pressure
Post by: Rubber_Snake on April 04, 2020, 07:08:13 pm
CONGRATULATIONS!!!
Title: Re: Front Won't Build Pressure
Post by: okrider on April 04, 2020, 07:12:02 pm
CONGRATULATIONS!!!

Thanks! I needed that!
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 05, 2020, 10:03:17 am
Yahoooooooooo!!!!!

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: okrider on April 05, 2020, 10:55:41 am
Well, poop.. I left it with the ziptie on overnight, just went to check, and there was no brake pressure until I pumped it a couple times. I'm going to reverse bleed one more time, see if I get anything out, and then order a master rebuild kit..
Title: Re: Front Won't Build Pressure
Post by: Rubber_Snake on April 05, 2020, 11:09:17 am
Well, poop.. I left it with the ziptie on overnight, just went to check, and there was no brake pressure until I pumped it a couple times. I'm going to reverse bleed one more time, see if I get anything out, and then order a master rebuild kit..

 :censored: 

I’d get the rebuild kit.  Need to rule that out. 
Title: Re: Front Won't Build Pressure
Post by: okrider on April 05, 2020, 11:29:34 am
Just ordered the rebuild kit.. Waiting on a big set of crush washers as well as I don't want to keep reusing the ones I got.. I'll replace all crush washers with the master rebuild once that arrives, in the mean time, going to check the calipers for any leaks..
Title: Re: Front Won't Build Pressure
Post by: okrider on April 05, 2020, 12:11:52 pm
Weird thing is, it kept pressure overnight before I did a test ride, and the bike was on the center stand. Left it on the side stand with the wheel turned left and the lever ziptied after the test ride and then I had no pressure in the lever. This is so confusing..
Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES on April 05, 2020, 02:49:07 pm
I'm just going out on a limb, and suggesting replacing ALL of the bleeder fittings with new ones, and re doing the bleed, normal bleed, not assisted bleed. I think your fittings are the culprit.
Title: Re: Front Won't Build Pressure
Post by: okrider on April 05, 2020, 04:21:30 pm
See, that would make sense if I didn't have speed bleeders, I've been swapping them back and forth at the calipers unfortunately to be able to do a reverse bleed. The problem with that is that the plumbers tape on the bleeders is getting torn and it leaks at the caliper fittings when I loosen it to bleed. I bought some plumbers tape today to put on the speed bleeders for when I install them back on the calipers.

Is it possible for it to leak air while it's tight?
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 05, 2020, 05:17:36 pm
MOB might have a good point.
Did the problem start after you installed the speed bleeders, or before?

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: okrider on April 05, 2020, 05:25:54 pm
Problem started after I rebuilt the calipers, I believe I had the speed bleeders at that point as I bled the system it seems early February. I don't see any fluid leaks or anything, and there's no air coming out of the bleeders which makes me think it's not the bleeders that are leaking..

I guess I'll switch the caliper bleeders back to speed bleeders with new plumbers tape to see if it still has an issue while sideways..
Title: Re: Front Won't Build Pressure
Post by: okrider on April 08, 2020, 12:34:23 pm
Update: Still waiting on the master rebuild kit. Still don't see any leaks. Bike holds pressure unless I go for a ride. If I go for a ride and come back and ziptie the lever, the pressure disappears an hour or two later. I just bled it while it's in this state, didn't see any air anywhere. Going to see what happens after I rebuild the master with new parts, if that doesn't work, going to install the used calipers I got..
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 08, 2020, 02:20:28 pm
Fingers are crossed for ya Buddy.

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on April 08, 2020, 02:23:41 pm
+1
Title: Re: Front Won't Build Pressure
Post by: Daytona_Mike on April 09, 2020, 01:10:26 pm
Same here... I am sure  it will be fixed with a master rebuild kit. I was on a Facebook site and what appeared to be the  same issue was fixed with a kit..  Good Luck!!
Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES on April 09, 2020, 02:52:29 pm
keep in mind "bleed down" on fluid pressure, differs from "air ingress'. and should be treated accordingly.. they are completely different, and come from differing issues.. 'member how I mentioned that air ain't coming in thru the master cylinder?, on another issue..? loss of pumping pressure can come from damaged seals, but as there is no "air" issue, it's just loss of "first pump" compression on fluid. Seal replacement is the cure.
Title: Re: Front Won't Build Pressure
Post by: okrider on April 09, 2020, 04:10:50 pm
keep in mind "bleed down" on fluid pressure, differs from "air ingress'. and should be treated accordingly.. they are completely different, and come from differing issues.. 'member how I mentioned that air ain't coming in thru the master cylinder?, on another issue..? loss of pumping pressure can come from damaged seals, but as there is no "air" issue, it's just loss of "first pump" compression on fluid. Seal replacement is the cure.

Yes, there's a chance the calipers are faulty still for one reason or another. That's why I have used calipers sitting in the garage, in case the master rebuild doesn't fix it.

At this point, first pump pressure is lost only after riding the bike, which I think is very weird.. It might be because the pistons actually move back and forth and calipers might be leaking as the pistons come in and go out.. They work fine while on the bike, seem to have constant pressure. But once I'm home and I put the ziptie on, 2 hours later, lever feels empty

 I don't know at this point. I just want to ride my bike reliably again :)
Title: Re: Front Won't Build Pressure
Post by: okrider on April 11, 2020, 05:37:15 pm
Replaced the internals of the master today with new OEM one. Putting that seal on the little piston was quite difficult. Bled as normal, top first, then calipers. Went for a ride and put the ziptie back on. We'll see if it holds pressure until tomorrow.

The test ride felt great, it was like test riding a new bike, brakes were confidence inspiring. I really hope they stay that way tomorrow. I'll come back and report yay or nay.
Title: Re: Front Won't Build Pressure
Post by: Daytona_Mike on April 11, 2020, 07:11:55 pm
Good news... glad to hear
Title: Re: Front Won't Build Pressure
Post by: Rubber_Snake on April 11, 2020, 08:14:43 pm
Fingers crossed!
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 12, 2020, 05:02:12 pm
Fingers crossed!

+1 !!

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on April 12, 2020, 05:18:30 pm
Come on now.  This thread is only 8 pages...  Let's keep it going!
Title: Re: Front Won't Build Pressure
Post by: tweeter55 on April 12, 2020, 05:55:17 pm
Come on now.  This thread is only 8 pages...  Let's keep it going!
I’m pretty sure okrider doesn’t feel the same way. LOL
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on April 12, 2020, 07:49:01 pm
Hmmmmm, you again....  LOL
Title: Re: Front Won't Build Pressure
Post by: okrider on April 13, 2020, 08:06:52 am
@VirginiaJim, if you'd like to take over the thread, I'm happy to do a caliper rebuild job on your bike, and you can try to figure out why your brakes aren't working while I ride my bike around  ;D

Good news everyone, it seems the bike is fixed after the master rebuild. Holds pressure overnight. Thanks to everyone who chimed in with suggestions and to everyone who gave moral support along the way.

Is there a lesson to be learned here? If you're rebuilding calipers, rebuild the master at the same time? Or is the master rebuild a bandaid over the "real problem"? I don't know but I'm happy I have a working bike now.
Title: Re: Front Won't Build Pressure
Post by: tweeter55 on April 13, 2020, 10:55:08 am
I will forgo the dancing bananas & just say:
CONGRATULATIONS!!!
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 13, 2020, 11:04:00 am
In this case, ya gotta do the Dancing banana's!!!


:banana :banana Yahoooooooooooooooooooooo…!! :banana :banana



Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: tweeter55 on April 13, 2020, 12:10:11 pm
 :rotflmao: :rotflmao: :rotflmao: :goodpost:
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on April 13, 2020, 01:05:21 pm
Just wondering why the master would need to be rebuilt as well?  Unless the pressure of the rebuilt calipers overwhelmed a worn master cylinder.  All the bleeding pushed it over the edge.  At any rate glad it's fixed!
Title: Re: Front Won't Build Pressure
Post by: okrider on April 13, 2020, 04:44:32 pm
Thanks people for the congrats. Going for a test ride today to pick up some Hattie B's, I noticed that the clutch could be smoother, and likely has air in the system. Maybe I should rebuild the clutch too while I"m at it. Now that I know how to do it..
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 14, 2020, 08:31:50 am
I don't recall okrider telling us why he rebuilt the caliper's?
Wondering if he had a master Cylinder problem in the beginning, and repaired calipers?
Id that a possibility?

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: okrider on April 14, 2020, 11:07:42 am
Well, that's a big kick in the nuts. During my ride yesterday, my brakes were quite good, and today they were much worse, ziptied the lever after a quick test ride, and an hour later, the lever's dead. No pressure at all..

The reason I rebuilt the calipers was because I could hear the bike braking as I was riding around after my road trip to Texas this past December. So I figured I'd rebuild them and sure enough, I can't hear the brakes dragging anymore, so something must've worked. But that led to this series of problems..

I think I'm going to bust open the used calipers I bought and give them a good clean and install those.
Title: Re: Front Won't Build Pressure
Post by: j_wahl91 on April 14, 2020, 12:52:48 pm
Well, that's a big kick in the nuts. During my ride yesterday, my brakes were quite good, and today they were much worse, ziptied the lever after a quick test ride, and an hour later, the lever's dead. No pressure at all..

Something tells me the dancing bananas jinxed it. Either that or Jim has a voodoo doll of your ride and he's been playing poke the brakes on it
Title: Re: Front Won't Build Pressure
Post by: robertv on April 14, 2020, 12:56:26 pm
Silly question, but checking to be sure- you are using DOT 4 brake fluid? Synthetic or not?

Title: Re: Front Won't Build Pressure
Post by: okrider on April 14, 2020, 04:38:12 pm
I blame the bananas too. Using DOT4, synthetic I'm pretty sure. It's valvoline brand
Title: Re: Front Won't Build Pressure
Post by: turbojoe78 on April 15, 2020, 05:46:10 am
You comment quite often about zip tying the lever after you have problems.  Have you tried just bleeding and not zip tying?  Could zip tying the lever down, keeping constant pressure on the brake system have anything to do with your problems?

The normal state of the system when not in use is relaxed, no pressure on pads or calipers.
Title: Re: Front Won't Build Pressure
Post by: okrider on April 15, 2020, 08:26:32 am
I have tried bleeding and not ziptying, the pressure was a little less, but there was some pressure when I did that.

It's common practice to ziptie the lever shut overnight to let air bubbles escape. It also tells you if there's a problem with the system which seems to be the case with mine.
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 15, 2020, 10:32:42 am
Ok, ok, Ohhhhtay!! I'll take the heat...
It's my fault.
No more dancing banana's..

       :1DeadBanana

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim on April 15, 2020, 02:17:29 pm
You know, nothing else was cracked open but the master cylinder and the calipers.  It's got to be something with the caliper rebuild.  I hope that the 'new' ones help you out and you can put this to bed.
Title: Re: Front Won't Build Pressure
Post by: Freddy on April 15, 2020, 06:51:30 pm

It's common practice to ziptie the lever shut overnight to let air bubbles escape. It also tells you if there's a problem with the system which seems to be the case with mine.

That's an old wives' tale.  From where do bubbles escape?
Title: Re: Front Won't Build Pressure
Post by: okrider on April 16, 2020, 07:56:18 am
they rise to the master reservoir? Either way, it's supposed to be able to hold pressure overnight
Title: Re: Front Won't Build Pressure
Post by: connie_rider on April 16, 2020, 08:49:22 am
Freddy, someone accidentally discovered that storing with the levers partially compressed overnight allowed the system to improve. 
Many (including me) have tried it {on a hard to bleed system} and it does seem to help.
The only think I can think of that seems to make sense is; pulling the lever back compresses' the trapped air, and opens a valve in the master cylinder that allows compressed air to migrate up into the reservoir.

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: kzz1king on April 16, 2020, 01:27:36 pm
I have used this method for years and it seems to help. I just changed pads in my 14 and the front didnt seem like it wanted to pump up like it should, just came back closer to the bar than it should. I pumped it up and put an small bungee on it and it seems good now. At any rate it did not get any closer to the bar under pressure because I measured the space in the evening and then the next day.
Wayne



Freddy, someone accidentally discovered that storing with the levers partially compressed overnight allowed the system to improve. 
Many (including me) have tried it {on a hard to bleed system} and it does seem to help.
The only think I can think of that seems to make sense is; pulling the lever back compresses' the trapped air, and opens a valve in the master cylinder that allows compressed air to migrate up into the reservoir.

Ride safe, Ted
Title: Re: Front Won't Build Pressure
Post by: Freddy on April 16, 2020, 06:45:57 pm
they rise to the master reservoir? Either way, it's supposed to be able to hold pressure overnight

That's not so.  Any air trapped in the line cannot escape/rise into the reservoir because the port thru which it would enter the reservoir is closed when the lever is moved from the released position.  Check how a master cyl works.

It may allow any air to rise to the master cyl so that when the lever is released, it immediately enters the reservoir.
Title: Re: Front Won't Build Pressure
Post by: kzz1king on April 16, 2020, 07:52:09 pm
I had to check it out and you are correct. Now you have me wondering if its  all in my head or does it work. Maybe its the constant pressure on the bubbles and than they are released like you mentioned.


That's not so.  Any air trapped in the line cannot escape/rise into the reservoir because the port thru which it would enter the reservoir is closed when the lever is moved from the released position.  Check how a master cyl works.

It may allow any air to rise to the master cyl so that when the lever is released, it immediately enters the reservoir.
Title: Re: Front Won't Build Pressure
Post by: MtnRider on April 17, 2020, 07:20:51 am
With pressure in the system, the air bubbles would compress. Wouldn't the smaller bubble size move thru the hoses easier?
Title: Re: Front Won't Build Pressure
Post by: okrider on April 17, 2020, 03:37:06 pm
I swapped out the right caliper for the new one, tried swapping the left one, it kept leaking from the banjo bolt, pretty sure it was cross threaded and so that's junk.

But either way, I'm at square one right now, no leaks, tried reverse bleeding the right caliper, no air came out. The left one still has the speed bleeder, so going to switch that to a OEM one and reverse bleed that one, see if I get anything. Then if no pressure, rebuild the master again since that helped tremendously last time.
Title: Re: Front Won't Build Pressure
Post by: Rubber_Snake on April 18, 2020, 11:00:31 am
Okrider,

I just had this thought (I don’t get many), but, is it possible, that when you rebuilt the calipers, you may have installed one of the seals in backwards?  Has this been brought up yet over these last 9 (now 10) pages?  I’ve never rebuilt the calipers myself, but I understand that if the seals are not in the correct direction, they will not keep pressure and leak.  I wonder if you haven’t been able to see fluid coming out of the calipers near the piston/pad area because the leak is so slight.  Maybe, just maybe, this is the problem? 

Ray
Title: Re: Front Won't Build Pressure
Post by: Rubber_Snake on April 18, 2020, 11:44:02 am
I checked and saw that VJim did ask about this, and the conclusion was that they are square cut seals.  Is it possible that they are not square cut?  Is there somebody here that can confirm?  Perhaps checking with Murph?  The problem started when you rebuilt the calipers.  The caliper rebuild  must be the problem.  It sucks that one of the used calipers has a cross thread.  I think you’re so close to having your problem fixed. 
Title: Re: Front Won't Build Pressure
Post by: okrider on April 18, 2020, 01:02:46 pm
I can confirm they are square cut seals. I inspected both old and new seals to see if there's a direction to them. There's not
Title: Re: Front Won't Build Pressure
Post by: okrider on April 26, 2020, 02:24:49 pm
No real update, my clutch was leaking at the slave so I replaced the seal but it kept leaking so I ordered a used slave cylinder and that seems to have solved the problem. Back to brakes, I went back to the OEM bleeders on both calipers (keep in mind right is used off eBay and left is mine rebuilt). Reverse bled the left as I had reverse bled the right last time I touched the bike, then "rebuilt" the master with the same components again as that helped tremendously with feel last time, no such luck this time. Removed each caliper and inspected for leaks at pistons, no visible leaks or anything unlike my clutch slave which was making air bubbles as it leaked fluid

The clutch and brake levers feel about the same resistancewise the brake is slightly more difficult to pull but not by much, not enough to inspire confidence..
Title: Re: Front Won't Build Pressure
Post by: okrider on April 27, 2020, 06:46:34 pm
The new clutch slave is also leaking for some reason.. I'm going to put the new seal on the used slave I got to see if that helps.

In the mean time, did a test ride after much bleeding, let it sit with a ziptie, and I lost all pressure again. I wonder if it has to do with air in the lines expanding with engine heat and then shrinking when it cools. But I also ordered a left caliper, it's the one I couldn't change before as the one I got was damaged, so going to replace that to eliminate that possibility.
Title: Re: Front Won't Build Pressure
Post by: tweeter55 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?
Title: Re: Front Won't Build Pressure
Post by: okrider 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..
Title: Re: Front Won't Build Pressure
Post by: fartymarty 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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.



Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: Freddy 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. 
Title: Re: Front Won't Build Pressure
Post by: okrider 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.
Title: Re: Front Won't Build Pressure
Post by: okrider 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.
Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES 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.
Title: Re: Front Won't Build Pressure
Post by: Freddy 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:
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES 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.
Title: Re: Front Won't Build Pressure
Post by: Freddy on April 30, 2020, 06:47:00 am
 :goodpost:
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: okrider 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?
Title: Re: Front Won't Build Pressure
Post by: Freddy on April 30, 2020, 03:53:45 pm
Water is best if on pads, then spray.  Good luck with it.
Title: Re: Front Won't Build Pressure
Post by: VirginiaJim 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.

Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES 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..

(https://shop.advanceautoparts.com/wcsstore/CVWEB/staticproductimage//N3221/large/7060459_crc_05089_pri_larg.jpg)

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..
Title: Re: Front Won't Build Pressure
Post by: Freddy on May 01, 2020, 01:44:00 am
'..........and you coulld go ride' and we could have some peace.    :rotflmao:
Title: Re: Front Won't Build Pressure
Post by: okrider 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
Title: Re: Front Won't Build Pressure
Post by: MAN OF BLUES on May 01, 2020, 03:25:49 pm
'..........and you coulld go ride' and we could have some peace.    :rotflmao:

hey now.. play nice... don't change my words, I'm only trying to help nicely.  :hail: :chugbeer:
Title: Re: Front Won't Build Pressure
Post by: okrider on May 04, 2020, 08:49:59 am
Through my post on Facebook, I've found out that losing pressure is normal if the ziptie is put on while the bike's hot as someone else has had the same issue. I'm going to call it fixed as it holds pressure overnight if I put the ziptie on when cold! Opened a new bottle of brake fluid as the one I've been cycling through the system is over a month old at this point.

Took the brake pads out, cleaned w/ brake cleaner and scrubbed with sandpaper and it felt a little better afterwards, I think I just need to keep riding for the pads to re-mate with the rotors. Broke the little clutch slave spacer while installing it because I didn't pay attention to its orientation, got one off eBay for $7 and put that on yesterday.

I think I'm going to ride the bike like this for a bit and see how it feels. Thank you to everyone for your comments and words of encouragement.