Complete Front Brake Fail

On the way to coffee this am, the front brake was
ok, needed a touch of pumping to get
full action.
On the way back NO front brake at all.
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Got home;
I took off the front calipers and sprayed
brake cleaner on the pistons 'guessing' that
one of them might be jammed up (?),
and was able to compress calipers on both sets
to the point that all pads compressed fully
so that opposing shoes came together normally
as I am used to seeing.
---
I re-bleed the top bleeder, no problem there,
but the bottom bleeders would not bleed,
when opening the nipple the hand lever wouldn't
even budge, and no brake fluid came out of either
bleed nipple.
---
Is a New master cylinder 'probably' needed?

I re-bleed the top bleeder, no problem there...

but the bottom bleeders would not bleed,
when opening the nipple the hand lever wouldn't
even budge, and no brake fluid came out of either
bleed nipple....

Is a New master cylinder 'probably' needed?

Based on what happened while bleeding, seems the master cylinder is normal. Fluid is passing through it.

The next in line is the RH caliper and it won't bleed. There's something blocking the fluid AFTER the MC. The LH caliper is third in line but if no pressure gets to the RH caliper, no pressure can get to the LH caliper either.

I think something is blocking the fluid after the MC.

* Last updated by: Rook on 7/3/2026 @ 6:16 PM *

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If you can press the pistons in with your fingers, that would seem to indicate that there is no obstruction there but where is the fluid going if it leaves the calipers? It has to go back up the line to the MC. If there's an obstruction after the MC, how is fluid going back to it from the calipers?

New idea: no obstruction after the MC. The master cylinder is bleed-able because the there is very little resistance while the top bleed is open. Close the top bleed, pump up the pressure, now nothing will come out of the bottom bleeds. Possibly the MC works, just not when it has a reasonable amount of pressure to handle. WHY? IDK. The bike fell over, the reservoir had a lot of sediment in it, maybe it washed down the hole all at once when the bike fell.

You could try a master cylinder rebuild first. If that doesn't work, you'd have spent a small amount of money to eliminate that as the cause of the problem. Otherwise, try a new MC and see if it fixes the problem.

The cheapest and easiest thing would be to change brake lines. If that didn't solve the problem, at least you'd have some cool aftermarket brake lines on there. Go with a double banjo at the MC and one line to each caliper instead of the loop over the front fender setup. I don't think it's brake lines though. You wouldn't be able to press the pistons in if that were the case.

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Opening the caliper bleeder and does not pass fluid is a clogged bleeder bolt. Might want to spray brake clean at and into the bleeder bold to flush out or dislodge the buildup in the bleeder bolt. Use a pointed scribe or small finishing nail. Spray to see the holes are reopened.

The bleeder at the master is to pump and press the lever, pull the lever to the grip and open the bleeder. Close bleeder before lever hits the grip. Pump again and open the master's bleeder again, close bleeder before lever hits the grip.

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I don't think it's brake lines though. You wouldn't be able to press the pistons in if that were the case.

Thanks Rook.

Might want to spray brake clean at and into the bleeder bold to flush out or dislodge the buildup in the bleeder bolt. Use a pointed scribe or small finishing nail. Spray to see the holes are reopened.

Thanks Hub,
I did not spray brake cleaner into the bleeder orifice
yet I forgot this part and don't know if I have the
skinny straw for the can.
I stuck thin screw driver in both valves, it went in
about 1'' and clanked like hitting the inside of the
apparatus on both calipers.
I'm able to get about two drops 'literally' out of
both bleeder valves if I squeeze pretty hard on the
lever.
The lever will only compress to within an inch/25mm or
so to the throttle grip.
(I DO have a 'stop' attached
to the grip also to keep it from hitting the grip,
as you instructed,, but that is only a 1/2'' stop)
1. Next steps?; Remove threaded bleeders, spray brake cleaner
into the holes?
2. Remove banjo bolts on both sides, disassemble ,clean?

EDIT; I found a couple of spray straws.

//

* Last updated by: Stratovarious on 7/4/2026 @ 6:34 AM *

1. Next steps?; Remove threaded bleeders, spray brake cleaner
into the holes?

I would do that if squirting them while open and on the caliper doesn't cure the problem. I'd only clean the RH caliper bleeder first, the LH might be fine. If the RH doesn't cure it, squirt the LH. If that doesnt cure it go back to the RH, remove it and squirt. You'll probably be able to see through it if you hold it up to a light. If still not cured, remove and squirt the LH. If none of that cures the problem, the bleeders are fine. The only way I can see cleaning banjo bolts is to remove them and try squirting cleaner through them. If it comes out the other end, the banjo is clean. Repeat the order with the banjo bolts starting at the MC, then RH caliper and if neither of those cure the problem after testing, clean the LH caliper banjo. Still not working, do the MC to LH caliper order of cleaning on the brake lines. The only way I can see cleaning brake lines is to use the MC to pump fluid through with the brake line disconnected on the other end. ...or get new brake lines.

The only thing after that is the calipers but you already moved them manually. I imagine the brake system would have a lot more power than your hands. Think of trying to squeeze the rotor with your hands to brake! The brake system does it a lot easier.

The MC seems good (it's the only thing definitely working). The bleeders and lines are very simple. The calipers are mechanically complex. If it comes down to calipers, you will want to try disassembling them to clean if flushing with the brake system doesn't work.

Be a good learning experiment but I'd have a complete Berringer system in the back of my mind. Brand new, whole system, it has to work. Way cooler than OEM too.

EDIT; I found a couple of spray straws.

I hate how those things never stay stuck to the can. You buy more just for the straw.

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Does it have abs? Module may be stuck,its usually the back brake that acts up but it wouldnt surprise me if it affected the front as well. Loosen the line from the module and see if it frees up.If it doesnt have abs then never mind lol. I had to replace my module last spring.

* Last updated by: Daddyrabbit on 7/4/2026 @ 4:14 PM *

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The MC seems good (it's the only thing definitely working). The bleeders and lines are very simple. The calipers are mechanically complex. If it comes down to calipers, you will want to try disassembling them to clean if flushing with the brake system doesn't work.

Yeah, I guess the MC works or not right, very simple
piece of machinery, I couldn't draw a picture of how
they work from memory but it pumps or it doesn't right?
--
The straws always get lost, they attach the to the can
with a piece of tape, and whatever is in the can
it most likely going to eat the glue off of the tape
first couple of uses, or the grease from our hands,
eats it. They should affix some 1 cent plastic ring
with keeper around the can , so we don't have to
deal with finding them damn straws, or like you say
buy a new can just to get the straw..

Does it have abs? Module may be stuck,its usually the back brake that acts up

Yeah, I had that thought on the way home
for the TOTAL FAIL, as it definitely felt
'LOCKED OUT'.
I left the engine running when I parked it,
took off the seat, pulled fuse # 2 of the abs fuses,
since I'd defeated abs before, and nah, it was just
the same.

I still don't have fuel lines/hoses that stay on
the nipples, that sucks, so aggravating, I have
to hold them on the nipple and they are so
####### short that even though the hoses I
found seem to be perfect, they just pop right off .
The top bleedr isn't as bad as the bottoms, and
as Ya'll know the top is an 8mm nut, not 10mm like
the bottoms.
I need to grind down the thickness of one of my
10mm wrenches, make in thin or narrow depending
on how ya look at it, which might help a little.
----------
I'm thinking now that I should disconnect the
bottom lines and try to blow them out in
reverse to see if that might help dislodge
sludge if that is the issue.

* Last updated by: Stratovarious on 7/5/2026 @ 6:41 AM *

UPDATE;
May be a bigger issue than I/We thought.

Being ABS, I find 3 factory pressed line modules
inline with the overall front brake system, with
two 'hard' brass (?) lines/tubes leaving two of the blocks,
heading toward the back of the bike disappearing under the
fuel tank cowling, I'm assuming those two lines
are directly related with to the abs system.
I'm now returning my attention to abs, perhaps
some component, like a stuck valve etc ...??

...With both banjo bolts disconnected from
the front caliper assemblies, the brake lever
still will not even budge and brake fluid
does not come out at all via the banjo bolts,
I also find that due to the basic banjo bolt
design, I'll not likely to be able to come
up with a way to blow the lines out backwards,
and they run into factor press blocks as well,
as I may have mentioned.

* Last updated by: Stratovarious on 7/5/2026 @ 10:20 AM *

I couldn't draw a picture of how
they [MCs] work from memory but it pumps or it doesn't right?

I couldn't answer that one. I think the lines and bleeders are simple. The MC has a lot of parts working together. It seems like yours is working since you were able to bleed it.

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Those two lines you mention go to distribution blocks under the triple trees. From there they go to the module. Before mine stuck completely I could pull the fuse and it would function properly but eventually got to the point it just stayed stuck. I have a thread on the maintenance page that had pics of the module. It really sounds like the return valve has frozen. Theres a fella in canada that has brand new takeoffs for a couple hundred bucks. Relatively straightforward job,a good set of line wrenches helps.

* Last updated by: Daddyrabbit on 7/5/2026 @ 7:43 PM *

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It seems like yours is working since you were able to bleed it.

Seems so, since I was able to bleed the
top bleeder line.
(For readers; I was able to bleed the top bleeder line only,
not the two lower caliper bleeders)
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Here's a coincidence; I have a front brake master cylinder
for my dirt bike sitting on my desk, that I bought about
two weeks ago waiting to be installed, as my dirt bike's
front brakes flat out stopped working also.
In this case, I'm sure the issue is the MC, as there are
no leaks and the hand-lever freely travels to the throttle grip,
with no resistance and braking no action.
:smi

Those two lines you mention go to distribution blocks under the triple trees. From there they go to the module.

Thanks much.

Do I have options?
Can I plug-up the 'distribution modules', bypass them,
run two lines at the MC via double banjo bolt to each caliper?
(@rook had mentioned something related to running two
separate lines to each front caliper via a double banjo
bold at the MC).
---
If I got this part right, there are some valves in
the distribution blocks that are attached to the frame under
the triple tree?
Is there another valve in the
final block that is closer to the front wheel?
And more valves in the pump assembly?
The blockage could be in the pump assembly under
the tank or at the distribution blocks on under
the triple tree?
---
Either way, I do like having the krtc, and abs
has been useful at the rear wheel, but not a concern
at the front wheel.

Does anyone have an amazon or ebay link to caps
that I can use to plug-off the brass/copper lines
that are attached to the frame that head to
the abs module?
I'm ordering some braided lines, and hope to bypass
the abs module, and not remove it.

EDIT; I guess it's a flared, M10, female threaded end cap,
something like that, but not able to find a
perfect match yet.....

* Last updated by: Stratovarious on 7/6/2026 @ 8:53 PM *

Its going to affect the rear brake if you cut flow to the abs while its still in communication. There are no valves in the distro blocks up front, they are just a means to change over to soft lines. The only way you will be able to keep electronic function as well as the speedo if you pull the fuse is to replace the module unless you do a delete with a Brocks abs over ride that piggybacks into the module. But then you still lose ktc.

* Last updated by: Daddyrabbit on 7/7/2026 @ 12:24 PM *

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The only way you will be able to keep electronic function as well as the speedo if you pull the fuse

I guess critical for me is keeping ktrc, and speedo,
I've pulled the abs fuse #2 to delete abs, before,and
that worked out ok, still had speedo.
(I realize you're saying Brocks deal will kill krtc,
I don't want that, so maybe I don't kill it if I
keep the fuses in and do as planned without
Brock's delete kit?)
So can I just put a male plug in the two distribution blocks,
and change the front lines out, double banjo to branch off
two both front calipers? Then be able to keep krtc, and
then whether I have rear abs or not is not
a big priority for me.

Thanks Daddy Rabbit,
I ordered the double banjo braided lines this am
and then canceled after reading your post.
If you think what I'm thinking about doing
will work, I'll re-order.
I'll still need to cap of the brass
hard-lines, and I'm coming up with blanks
trying to find female 10M x 1.25 plugs, if
I even have the size right, everything I'm
finding even close is 10m x 1.0 thread pitch,
which supposedly won't work.
The opposite side of the distribution blocks
are integrated into the blocks, a factory
weld, so I can't just
plug them with male plugs.

* Last updated by: Stratovarious on 7/7/2026 @ 3:17 PM *