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My K1100RS Tried to Kill Me (ABS?)

112190

Bikeeuro2
'96 K1100RS SE w- 76K mi. Bike operating fine, 2 hours into our vigorous ride, until it hiccuped. Road surface was bad, and wasn't sure it was a hesitation at the time. Shortly thereafter, noticed red ABS light on. Didn't think much of it, as the system occasionally doesn't set up, and it's never impacted brake operation. Within 10 miles, riders ahead signaled a left turn, and I initiated braking,.....only nothing there. STOOD on both brakes and got basically NOTHING. Overshot the turn while downshifting as fast as possible. Got on shoulder, but couldn't get bike stopped, and was now beginning a downhill descent, in unfamiliar territory. Fortunately, no traffic either way, so made a decision to attempt a u turn. Not enuf road, and front tire washed out in the crowned gravel shoulder on the opposite side of the road. I got off gracefully, and was unscathed, but what used to be an SE that'd never been down, is now something else. More importantly, I remain surprised and unhappy that a bike I've ridden 40K in recent years could have done this to me. Speeds were near triple digits at times earlier in the ride, and I can't help thinking about how bad this could've been.

Bike trailered home, and has not yet been taken to mechanic for diagnosis. GoAZ (Scottsdale dealer) technician says it's uncommon but not unheard of to have brake failure w- this vintage Kbike. In fact, he told me he currently/recently had one come in where the brakes just seized!!!

Just wanted to get word out. I knew I was exposing myself to many risks,......but this one wasn't one of 'em. Might be awhile before I get back on a modern motorcycle (I assume the Gen 2 ABS will be found at fault for this episode). And I would've ridden an airhead if the temps in PHX weren't 110 on the day in question!

Wm
 
Wm,

Did the brake lever and pedal travel further than usual or were they "high and hard" but just did not stop.


After you answer that, when was the last time the brake fluid was changed and did you use dot 4?


:dance:dance:dance
 
Reply

High and hard.

I think brake fluid changed 18 months, and 2500 miles ago. I'll check with the mechanic on the Dot 4? There WAS plenty of fluid after the event in question and, after re-start, with some ugly electrical noises (fuel pump?), the brakes worked, and I rode it 2 and a half miles.
 
WTH did my brakes go?

#1 Glad you are Ok .

#2 High & hard. IMHO you smoked the brakes. I was NOT there, but this sounds like a case of glazing the rotors by over heating them and exhausting the friction available with the type of brake pads you have installed.

#3 Again, IMHO you need to change the brake fluid more often, but that's not the problem here. I beleive this should be an annual service on a " K " bike and many other models. I OVER do my 93 K11RS and do this in the spring AND in the fall. DOT 4 is cheap and I get it done in less than an hour.

In closing and all IMHO again, the K1100's are heavy bikes. If you are really pushing them, sounds like you can and after 76 some odd thousand miles you know that bike well, it's time for a brake upgrade. You did not say if the brake lines were stock. If they are and you decide to trust the bike, treat it to new lines from Spiegler of the like.

Best of luck and please do report back on what the dealer says is wrong.
 
fluid changes are probably fine, as 18 months is (most likely) totally reasonable in the desert SW (assuming that is the nature of your part of AZ, rather than up in the higher hill country) to put off fluid changes- which are done to counteract the hygroscopic nature of brake fluid. but if there's little moisture in the air, there's no reason to be pathological about fluid changes.

look for a plugged return line in your brake master cylinders, internally ruptured hoses or similar system breakdown. ABS failure is not a likely cause for the brakes to go hard on you.

are your brake lines still the stock rubber ones? if so- get rid of them NOW!
 
Reply 2

thanks for the input.

Bike going to Omar @ Motoghost in PHX today. I should have a diagnosis w-in a couple days, and will certainly post it.

I have Multiple Bike Disease, so it's a little hard to recall features on each bike. My guess is that this scooter has it's original rubber brake lines (my '76 R90S still has it's originals too - but not for long).

I am beginning to recognize my own contribution here. When you have numerous bikes, and you aren't much of a wrench, it's easy to overlook the importance of annual maint, regardless of mileage. I know better than to focus on mileage as opposed to the passage of time. I'm afraid I lulled myself into thinking that since this unit wasn't being ridden, I could stretch the service interval a bit.

Sorry to rush to judgement on the Gen 2 ABS,.....we'll see. It's been a great old bike, and I think this is it's 1st time on a trailer. Just a shocking experience though.
 
Yes, more likely a brain problem than maintenance related. It's no way in heck the difference between dot 3 or dot 4.
 
It's no way in heck the difference between dot 3 or dot 4.

That's why I asked the "high and hard" question. If the answer was that the pedal "went to the floor" or was extra spongy, the I would suspect fluid boil. Dot 3 has a lower dry boiling point than Dot 4 and a significantly lower wet boiling point. That's why I use Ate Super Blue Racing brake fluid alternated with their identical Type 200. They have significantly higher dry boiling point than any readily available brake fluid, but more importantly, the WET boiling point is the highest I've seen. It is a Dot 4 fluid.



:dance:dance:dance
 
Reply 3 - Preliminary Diagnosis

My mechanic says that it appears the Odyssey battery's pos terminal grounded out against the bracket that is right on top of it, causing the ABS brain to malfunction and, despite that the brakes were fully capable of functioning, the ABS system was telling them BOTH to release. I am responsible for installing the battery and, ultimately, the cause of this. Nevertheless, I remain chagrined that the safety feature can fail and take us out. Not sure what this bike's fate will be, but I am pretty sure I'll stick with airheads and an older VFR w- no ABS from here on out.

More in a a few days after the mechanic has a chance to delve in. I've told him I want a clear diagnosis.

Interesting to hear that I am not alone. I just never understood I faced such a risk. I thought Bambi would get me before a safety system decided to deprive the brakes of their mission.

Wm
 
Wow - great to know this. Thanks for sharing as we can all benefit from your experience on the pos/ground situation :nod
 
Reply 4 - Fish Response

B-Fish,

Astute observation. I have accepted some role in this as a mechanic as opposed to a rider. Whether I should be acquiring more tools and working on anything with two wheels that I will ride hard is a question deserving of some thought. Additional thought may involve how it is that a safety system could tell two perfectly good braking components NOT to brake when the rider is standing on both. alowing hte system to override manual input under these circumstances just bewilders and frightens me.

I only hope I am right that an Airhead would never think of trying to take over the controls!

Wm
 
an airhead, or even an earlier edition K bike, would not do that. in fact, any non-ABS model would ensure no ABS over-ride of your requests. of course, airheads (especially the twin shock models) have their own version of ABS, but most of us just think of them as inadequate brakes.
Of course, you can always opt to switch off the ABS on your K11RS manually (that rocker sw on the handlebar dash), or just disconnect/dismantle/remove the whole thing if you are that freaked out about it.

the entire functional purpose of an ABS system is to over-ride the rider's inputs, when they are seen to be too heavy handed.
also, be aware that the ABS system's have gone thru at least 3 iterations of improvement since your bike was developed, so they are better. but I doubt that any are entirely fail proof. they are, after all, a electrical/mechanical system, and all systems can fail.
 
Reply 5 - B/Fish Nails it

B-

Thanks again, and we are entirely in agreement.

You make 3 excellent observations. First, since I am a poor wrench, I still experience surprise and chagrin when mechanical components fail in unpredictable and odd ways. If I am to become a minimally competent wrench (all I can realistically hope for), I must overcome this notion that stuff will function the way I expect it too.

Second, I AM freaked out, and it's because I long ago accepted many risks like driver stupidity, Bambi, blow-outs and substances on the road. Once again, my faulty sense of logic and rationality convincedme I had them pretty well catalogued, and would simply have to face them. Nope,......thre's no logic here - when your numbers up it's up.

Third, my trusty old Kbike can be as obedient as my precious airheads,.......I just need to sack the ABS. If I decide to have it put back on the road, that is exactly what should happen. As you rightly observe, even without ABS, the brakes are WAY better than the disc and drums I tolerate on the old twins,.....and better than what Honda put on my eager little '95 VFR.

Once again,....my appreciation for taking the time to help me analyze these issues.

Wm
 
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