Losing rear brake after a good bleed.

Jlq1969

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There's a difference between a warranty claim/defective product claim and a product safety issue.

Trying to prove a product is defective does open up all those counterclaims from a manufacturer that you neglected maintenance, or the product was used improperly outside its original intent.

If someone actually loses their brakes because an ABS module fails, then that's a whole different issue. A braking system still has to be able to function even if the ABS module fails. Under 49 CFR Section 571.135- Standard No 135; Light Vehicle Brake Systems, under S7.8.3, it says that for service brakes on a vehicle equipped with one or more antilock systems, in the event of any single functional failure in any such system, the service brake system shall continue to operate and shall stop the vehicle as specified in S7.8.3(a) or S7.8.3(b).

So if your actual braking system has failed because an ABS module failed, that's a violation of the consolidated federal standards for ABS, and is most definitely an issue that should be reported to the NHTSA. Under that CFR statute, it doesn't matter if you never changed your brake fluid, brake hoses, of let the module sit in swamp water for a year; the brake system has to remain functional in the event of an ABS module failure. It's a product safety issue. A complaint to the NHTSA isn't about "Yamaha/Bosch makes a crappy ABS unit and I want a refund" , it's about "Yamaha's braking system as designed doesn't comply with the federal regulations regarding antilock equipped braking systems".

If you can't get a functional brake in the rear after it's been properly bled, and the only way you can achieve a functional rear brake is to replace the ABS module, then this point needs to be driven home with the NHTSA. If you're being told by a Yamaha dealer or an independent mechanic that the only way to rectify the problem is to replace the ABS module, then that should be thoroughly documented in your complaint, with names, dates, times, written estimates, etc.

I don't really know how widespread this issue is, as far as defective modules go; forums are great for a lot of good things, but they're also great at confirmation bias. But even one failure of what is supposed to be a fail-safe system is too many.
If you google, rear brake fail, in Ducati…KTM…BMW GS….you will see that the problem is similar and repetitive
 

Jlq1969

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So all those models plus the Yamaha share the same ABS pump?
I don't know if the pump is the same... but the loss of the rear brake seems to be a problem for other brand/models as well…..same problem, rear brake…
 

RCinNC

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It's difficult to drawn any conclusions about the failure rate of a Yamaha ABS pump based on failures of different ABS modules. And without some actual scientific investigation on what the actual failure rate is of these pumps (the kind that maybe the NHTSA would conduct), and if all these failed modules share some sort of common characteristic, the only thing left is dependence on anecdotal evidence. Anecdotal evidence does have some weight, but it's not enough to draw any real evidence based conclusions.

That's why forums can reinforce confirmation bias. If someone begins a thread about their pump failure, and a few others post theirs, it begins to sound like an endemic problem. You read three or four accounts of a failure, then see three or four accounts on a BMW forum, and it becomes easy to draw a conclusion that an ABS pump or a particular model of bike has an issue. It may actually have a real issue, but self reporting on forums is a really unreliable way to determine that.

Like Steve in ATL said, the people that have these issues with ABS pumps that are resulting in brake failures should be reporting these failures to the NHTSA. It would likely be more worthwhile than hashing it out on forums. It's not a bad idea to bring it up on these forums so guys can evaluate it for themselves, but that alone won't result in any real examination of the problem.

Without a doubt, if people are experiencing brake failure as a result of a failed ABS pump, Yamaha is going to have to be forced to address it, and the only way to do that is to make formal complaints to the right agency.
 
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sportrider

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Add me to the list. 2015 es with 13k miles, bike was a leftover bought new in 2018, still on original rear brakes that have plenty of life left, had brake fluid flush at 12k miles, bike lives in Hawaii, road use only, developed spongy rear pedal. Two pump cycles bring rear brake back until I use front brake, then it goes spongy again. No warning lights on. My Hawaii bike is non USA bike and I was told it is not eligible for USA recalls. Apparently Hawaii dealers get their bikes straight from Japan. I will file with NHTSA.
 

Steve in ATL

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So I just finished and submitted my NHTSA safety notification. Looks like there are currently two other reports as well. I'm not holding my breath, but maybe soem day there'll be enough of a problem that Yam is forced to do something about it. In the meantime, I've ordered tubing and fittings, and we go non-ABS this weekend.
 

Jlq1969

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I hope you're lucky, and that the claim serves to provide a solution...... What I don't understand is where does the brake pump pressure go?...if the pump works well, and pushes fluid...where does that fluid go? ?
 

Steve in ATL

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I hope you're lucky, and that the claim serves to provide a solution...... What I don't understand is where does the brake pump pressure go?...if the pump works well, and pushes fluid...where does that fluid go? ?
Remember that fluid movement in a hydraulic system is pretty minimal, and very small amounts of air are needed to corrupt the system. So the amount of leaking would be minimal - my tray has a bunch of debris in it that's contaminated / glued together by what I'm assuming is hydraulic fluid.
 

bimota

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No I made up new pipes out of 3/16 copper brake line. I purchased long threaded M10 tube nuts x4 (eBay) so I didn’t wreck the original pipes.
The pipes are just a staggered U that bypasses each side of the ABS. The left 2 (looking forward) are the rear in and out.
The right 2 are the front in and out.
Just remove all 4 grey lines that go from the mounting block to the ABS unit, blank the ABS unit ports to keep the dirt out, I used aluminium tape.
Fit the U pipes, bleed and ride.
The ABS light cycles like it should on the dash with ignition and as the ABS ecu never sees any brake pressure it doesn’t fault.
My bike passed its road worthiness inspection even though the ABS doesn’t work
I would think any engineering outfit that can repair boat trailer brake lines would be able to fabricate them for you. Once the nuts are on the pipe they need flaring.View attachment 60508View attachment 60509
can i ask looking at your picture, is this by passing the whole of the ABS unit so no ABS at all or is this just rear by passed i,m guess ing all are now by passed

rob
 

bimota

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My vacuum bleeder turned up today so I had another play.
I made up a pipe to bypass the rear side of the ABS unit. Sealed up the bleed nipple with some thread tape and sealed the rear reservoir cap and sucked the system down to 20 inHg. It held at 20 for a good 1/2 hr.
I then made up a blanking pipe and tried to suck the rear side of the ABS unit but it wouldn’t hold and settled at 2inHg. View attachment 50418
Something inside the ABS unit is leaking air, my guess would be the seal on the shaft of the motor as everything else is sealed.
I made up another pipe to complete the rear side of the ABS,filled it with fluid and installed the pipe, bled the rear and went for a ride.
The rear brake feels fantastic, obviously no ABS but it’s so powerful it made me smile. Went down a gravel road and fired the front ABS several times and came home with no ABS faults.
I have had air introduced to the front brake twice now when using unified braking so I’ll either have to bypass it, fix it or replace it.
I’ll have a go at fixing it next time I’m feeling brave.
can i ask, in the above picture the 2 coppers pipes that are in is this just the rear brake by passed

rob
 

Steve in ATL

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can i ask, in the above picture the 2 coppers pipes that are in is this just the rear brake by passed

rob
The picture that you quote just the rear brake is bypassed. The tube on the right seals off the rear brake inlet / outlet ports of the ABS pump. The tube on the left joins the incoming brake pressure from the pedal to the outgoing tubing to the brake itself.

See my earlier post for what it looks like with both brakes bypassed.
 

bimota

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The picture that you quote just the rear brake is bypassed. The tube on the right seals off the rear brake inlet / outlet ports of the ABS pump. The tube on the left joins the incoming brake pressure from the pedal to the outgoing tubing to the brake itself.

See my earlier post for what it looks like with both brakes bypassed.
ok got it looking at your picture you have gaffa tape over your abs module with no pipe connection to it and you have 2 pipes away so you have by passed the hole pump all togher

cheers rob
 

Steve in ATL

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ok got it looking at your picture you have gaffa tape over your abs module with no pipe connection to it and you have 2 pipes away so you have by passed the hole pump all togher

cheers rob
You are correct sir. Are you thinking of doing this to your bike? If so, make sure you leave the output side of the new tube loose and bleed there before tightening down. Then finish bleeding at the brake. If you have air in the tube when you install it and tighten it down it can disguise a leak (though not for long), and it saves time overall on bleeding.
 
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