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I put new pads on before I left on this trip. All good for over a thousand miles.

Now, when applying front brake the ABS randomly starts thumping, not all the time, randomly, release and sometime goes away, pump it a couple times then it goes away for sure. Then it randomly comes back during braking. There doesn’t seem to be any particular reason. Fast, slow, light application, hard application. It also goes away if I tap the rear brake while it’s doing it.

Cursory Inspection show the pads in the their place correctly, and the sensor lines up correctly. We did kill about a billion grasshoppers and it seems to have started after that. I find it coincidental tho I don’t think a bug could cause that

Front brake was a little squishy when we just stopped for lunch. Kind of like when you put tires on and then pump them up. Then it was fine.

No visible fluid leaks.

Thoughts?

You parked your bike tooooo close to a BMW??

Front or rear rotors getting hot? Wonder if you have a brake dragging due to a crudded up pivot?
Other than that, I would pull the sensors and make sure they are clean. Good luck.

What are the symptoms of a master cylinder failure? I have no idea about wtf is up with the ABS, but if you've recently flushed the fluid, have no leaks and have a squishy pedal/lever...that's what would be in the back of my non-mechanical mind. That and that your bike is one of those weirdo Black FJRs parked WAY too close to a BMW.

Haven't heard of this exact symptom... kinda sounds like one sensor is telling the ABS ECU the wheel isn't turning (or turning slower than the other one) while braking, then it kicks in the ABS. I can only think dirty sensor or trigger wheel, or less so, faulty sensor. I'd inspect for bug guts and give them a wee wipe. Could also have corrosion (white flakes) on the sensor (from the adapter hole it goes in), for now wipe down and later some silicone/dielectric grease. Most conditions should just turn the ABS light on or flashing, not actually kick in the ABS.

Maybe a pad (or pads) separated from the backing. I've Seen that before with cheap replacements. Look up rust jacking brakes.

Just a thought.

I would go with pulling the sensor and making sure it is clean. If it is partially crudded up that could cause a intermittent sensing that the wheel isn't turning. Are you just applying the rear brake alone when it goes away? If so, then it is just looking at the rear sensor, so I would think that still points to the front sensor.

I know a guy with a shop in La Pine.

Bugnatr wrote: ↑Wed Sep 04, 2019 4:26 pm I know a guy with a shop in La Pine.

I heard he only works on Kawasakis and Beemers...

wheatonFJR wrote: ↑Wed Sep 04, 2019 4:31 pm

Bugnatr wrote: ↑Wed Sep 04, 2019 4:26 pm I know a guy with a shop in La Pine.

I heard he only works on Kawasakis and Beemers...

That's for the retired guys with WAY to much time and money.

I’m thinking front sensor. Going take it apart at Ray’s tomorrow.

0face wrote: ↑Wed Sep 04, 2019 8:53 pm I’m thinking front sensor. Going take it apart at Ray’s tomorrow.

Take movies!

Ummmm...I think I found the problem.

Loose Caliper. f@$king moron didn’t torque the bolts enough.

Dayum! He's fired!

Wadda Maroon!

You gonna wait till Lapine to fix dat?

EDIT: Hey, there would seem to be a straight forward fix for that. But that's just me.

This should be nominated for a "Post of the year" contest...

0face wrote: ↑Wed Sep 04, 2019 10:08 pm Ummmm...I think I found the problem.

Loose Caliper. f@$king moron didn’t torque the bolts enough.

Way cool. I’ve heard of floating rotors. But floating calipers is some next level shit.

Jeez, throttle cables coming loose under the tank, missing caliper bolts. What's next?

0face wrote: ↑Wed Sep 04, 2019 10:08 pm Ummmm...I think I found the problem.

Loose Caliper. f@$king moron didn’t torque the bolts enough.

All joshing aside, I'm glad you found it before bad stuff started happening.

So, did this explain the random activation of the ABS?