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Okay, I'm reaching the end of my rope. Here's what I did this weekend, and I still have the same problem of too much front brake lever travel.

My setup is stock, rebuilt front calipers. Stock, rebuilt master cylinder. New EBC brake pads. New Galfer steel brake lines, two independent hoses with no crossover, using a double banjo at the master cylinder. My problem began after I replaced/rebuilt this stuff. I threw the stock brake lines away, so I can't use it to test.

Here's what I did this weekend:
  1. I rebuilt the right front caliper again with new seals and hardware. Filled it with fluid, bled it with traditional pump and open method, no change.
  2. Thought I may be going crazy, so I again removed the double banjo at the master and installed the lines individually to see if maybe I was imagining the difference from left to right. Once again, solid lever with perfect travel on the left, too much lever travel on the right.
  3. Thinking it may be a stubborn bubble in the right brake line, I picked up a cow syringe and reverse-bleed. Put it back together, no change.
  4. Replaced the speed bleeders with standard bleeders, no change.
  5. Thoroughly pissed, I decide to rebuild an extra caliper I bought from Mad8v for the pistons. Luckily, I had an extra rebuild kit. This makes the third time rebuilding the right caliper. Zipped it back together. Same problem.

My thoughts: the only thing left is possibly a faulty right brake hose. It's a brand new Galfer steel-braided hose, but it represents the only thing in the brake system I have not changed since the problem began. Some have suggested a bad master cylinder, but if that was the case, would it not affect the left and right brakes equally? Could it be the double banjo is faulty?

Once again, I appreciate your input, and am hoping for some more ideas.
-Geo
Great post, Geo. If more folks had your equanimity the world would be a better place. No doubt you will solve this and everyone following this here thread will likely learn something. (y)

I agree the problem can not be the master cyl as it is common to both sides.

It is also unlikely to be the line. But you could prove that by swapping the "good" caliper over to the "bad" line and try again.

Maybe it is the angle of the caliper? This might explain the right vs left. If all this time you've been bleeding the right caliper with the handlebars turned one way, the caliper may be tilted in a position that traps air. Try turn the bars the other way and bleed again. btw, this is also important when "burping" the MC with light lever pulls. The handlebars need to be turned to the left to allow the trapped air to rise.

If that doesn't help, I would follow Kiwi's suggestion. Unbolt the caliper, raise it over the MC. Hopefully, your wife is not averse to getting brake fluid all over her pretty hands as this will likely be a two-person job. : -)

Hang in there you will solve this.
 

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Discussion Starter · #64 ·
Maybe it is the angle of the caliper? This might explain the right vs left.
That's an interesting thought Tee. Throughout this ordeal I have been bleeding them with the bike on the rear paddock stand. I'll use the sidestand and give it another shot. Otherwise, I will try Kiwi's idea. As a last resort, I will switch the left hose to the right and see if I get lever. Thanks guys.
 

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Our endurance Ninja 400 has had a freaky issue we’ve begun to narrow down. The single caliper, when fully secured to the fork, is tweaked slightly, causing the pistons to come out at an angle to the rotor, apparently allowing air in or pressure out or something. We had to watch closely to see the rotor deflect while squeezing the lever. If we loosen the mounting bolts (or take it off entirely), they work fine, except then we’d see the whole caliper move. Strangely, when it is getting pressure, it seems the pistons weren’t retracting, causing the pads to drag, making us slower, and burning thru a set of $120 pads in 3hrs.

It’s not been consistent, so we couldn’t even get this far in understanding for several months and races. We replaced caliper and lines, same deal. It is apparently the mounting stanchions(?) or some other part of the fork that is slightly tweaked, apparently from a crash by previous owner.

I’ve wondered if it’s possibly the mounting plate overheating as the pads drag, exacerbating this issue. It’s discolored
 

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Discussion Starter · #66 ·
Weird problem Shaggy. Discolored mounting plate, that thing is getting extremely hot.
 

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Discussion Starter · #67 ·
After reading Tee's and Kiwi's replies, I decided to give it a go this morning before starting my day. First I put the bike on the sidestand to see if bleeding at a different angle may be the issue. In the process I learned the lean angle on my bike when it's on the sidestand is quite steep. If I had opened the reservoir, brake fluid would have poured everywhere. So I put it back on the paddock and siphoned some fluid out before putting it back on the sidestand.

Thereafter, I bled the right brake some more using the traditional pump-hold-open-close method. I went through a bunch of reps, seeing no bubbles, and checked. Still, same problem, lots of lever travel.

Next, I tried Kiwi's suggestion. Only problem was, I was alone. And I did not intend to awaken Mrs. Geo-ette. So the genius in me decided to replace the standard bleeder valve with a SpeedBleeder. I removed the caliper and built a tower of chlorine boxes and a citronella candle to place the caliper above the MC.
Tire Wheel Land vehicle Vehicle Motor vehicle


SpeedBleeders are cool because you can just open them, and a check valve inside does not allow hair in. You just pump away. So that's what I did, and I found LOTS of bubbles. I refilled the reservoir and kept pumping. The bubbles would not stop. Ultimately, I found the SpeedBleeder was leaking air around the threads. I tightened it a little, and the bubbles stopped. I bled a few more times just for good measure and reinstalled the caliper.

With fingers crossed I pulled the lever a few times, nothing. Thinking it was simply a matter of pushing the pistons out, I pumped more. Nothing. I think I just successfully introduced a shit ton of air into the system with my loose SpeedBleeder. No matter how much I pump, I have no lever.

Advise from a dumbass: If you are going to use SpeedBleeders, make sure you don't open them too much, and that they have sufficient thread sealant. They come from the factory with thread sealant for a reason. On the other hand, like Drew suggested earlier, just take them off and throw them away.

(I realize I'll probably hear from brake experts who've been doing brake jobs for the last 50 years with SpeedBleeders with huge success. No worries, keep using them.)

So that's where I stand. I've got zero brake engagement, and a system filled with air. My next step will be to swap the left brake line to the right side to see if a faulty line is the issue. I know it's a long shot, but I'm running out of things to replace. BTW, if you are an investor, go long on Prestone. My brake fluid purchases will be reflected in their next quarterly earnings report. Cheers.
-Geo
 

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The photo shows the brake line angles down when exiting the master cyl. This is the exact place where the standing air bubble collects.

Try repositioning the line so it is vertical the entire way from the MC up to the caliper so air will naturally rise at all places in the line.

The MC banjo bolt will need to be slightly loosened to allow reposition. When done, the line can be moved back to the normal position.

Good job protecting the front fender. (y)

I am not a fan of SpeedBleeders either.
 

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In hindsight poor technique sounds insulting. What I mean was more that some (most) systems need odd techniques to best bleed them.

Common stuff is:
  • Requiring (after an initial bleeding of the majority of the air) many half strokes quickly to get the pistons pushed out to the disc (without which no pressure will build up)
  • On the pump pump pump hold the lever down, not holding it down long enough waiting for little amounts of air to dribble out before closing the bleeder again
  • Not closing the bleeder while the lever is still pulled in
  • Not pump pump pumping the lever before holding it down and cracking the bleeder
  • Not ensuring the bleed hose stays fully submerged 100% of the time during the entire operation (if the hole in your jar lid is tight on the hose it makes that easy)
  • Not ensuring the reservoir never runs dry (if it does, you start from scratch)
  • Not ensuring the bleeder is at the top (calipers on wrong sides)
  • Not priming the master cylinder before attaching the hoses (can be done after but it's messy and trick). Basically just 'bleed' the master with your finger over the outlet
  • Not elevating the calipers over the master (doesn't matter for changing fluid, but often helps with an empty system such as new lines would be)

I wouldn't worry about the calipers much, a blind leper could rebuild one. If it doesn't leak, there's no problem. You absolutely do need to half stroke the lever quickly to get the pistons all extended out and the slck between piston/pad/disc gone. Any gap there will rob all your pressure build up in piston stroke.

Speed bleeders are just tat, just keep your hose submerged.

You could prove the hoses are correct by switching sides, but I'd wager that won't be it.

The master is super simple and will probably also be fine, otherwise you wouldn't get the left bled up ok.
 

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Oh and don't bleed it like in that picture, rotate the caliper so the bleeder is the highest point. I know I've said that a couple of times, but it's important... gotta help that air find the path of least resistance and it wants to float up.
 

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Discussion Starter · #73 ·
Mystery solved! It was a fucking bad brake line. This morning I swapped the left brake line over to the right, hooked it up top with a single banjo, bled the system, voila...solid lever.

I used the syringe method to fill it up from the bottom, then I burped it at the MC until I saw no more bubbles. But, at that point I still had excess lever. Damn! So I pumped a few times and opened the caliper bleeder, and a big bubble farted out. Bled a few more times, and the lever was solid as a rock.

Happy day! Now I only need to figure out where I bought it and return it for another. I would not expect a Galfer line to be faulty, but it happened. Thank you all for your advice and encouragement. It helped a lot. In fact, this situation reminds me of a year back when I was trying to get the old girl running. It took a full month of tinkering, and volumes of advise and patience from you guys. But in the end, it worked, and she's been purring like a kitten ever since. So a heartfelt thank you goes out to the SVR braintrust.
-Geo
 

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Glad you found it. Just goes to show even ,"Brand " names can suffer from bad Q/C. Years ago I bought a pack of brand new Branded spark plugs and one of them was duff and another failed after a few hundred miles :O

On the other hand I've had Spark plugs do over 50,000 miles and have the original Denso plugs that came with my SV under me seat as spares and they were still firing well when I took them out around 26,000 miles :)
 
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Hmmm, I'm trying to imagine the fault mechanism for a teflon/stainless brake line. Did the teflon inner tube not extend into the banjo?
 

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Discussion Starter · #77 ·
Hmmm, I'm trying to imagine the fault mechanism for a teflon/stainless brake line. Did the teflon inner tube not extend into the banjo?
When I remove it I'm going to inspect it carefully and let you know. It may also be buggered on some of the surfaces where it bolts to the caliper and MC.
 

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When I remove it I'm going to inspect it carefully and let you know.
(y)

The professional skeptic (friends and family accuse me of being the worst, :D) would be swapping that line in and out with the other line, like 10 times, until certain the cause.
 
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