16 replies to this topic

[RCook]

Not always but more often when coming to a stop it feels like the ABS is engaging on a normal, non-panic stop. Just a little vibration in the lever but enough to know that it's the ABS kicking on. Short of something else is this indicative of wearing/worn pads? I have an '07 bought in '09 with less than 20K miles so I can't imagine the pads being too worn. Is this normal and I'm just getting used to the bike and braking harder now that I've got some miles or something I need to be concerned about?

[Ignacio]

I have an '07 bought in '09 with less than 20K miles so I can't imagine the pads being too worn.

Why don't you look at them for wear...it only takes a couple minutes to get the right angle for viewing and estimatin brake material. It should be a check you do at least once in a while.

Unless your pads are worn down and on metal or seriously unevenly worn...I doubt pad material is related to ABS kicking in. I also presume you're talking about the back brake. If so, it's been my experience you kick it in more as you get used to the bike.

[HotRodZilla]

Not always but more often when coming to a stop it feels like the ABS is engaging on a normal, non-panic stop. Just a little vibration in the lever but enough to know that it's the ABS kicking on. Short of something else is this indicative of wearing/worn pads? I have an '07 bought in '09 with less than 20K miles so I can't imagine the pads being too worn. Is this normal and I'm just getting used to the bike and braking harder now that I've got some miles or something I need to be concerned about?

I say you're probably braking harder, but the pads are very easy to check.

Take your calipers off (You may not even have to do that, but I think it makes it easier to get the pads back in).

Once they are off, remove the small Allen bolts holding the brass clips on. Be ready for your pads to fall out. Remove the clips and the pads and check them out. Clean up your pistons with a toothbrush and some brake cleaner and use a screwdriver to wedge them back in just a hair. Then put them back in the reverse of how you took them off. Should take you less than 10 minutes...Maybe 30 minutes the first time.

[SkooterG]

It's not the brake pads. And I am having a hard time believing your ABS is activating during 'normal' stops. IF it is, then there is something seriously wrong with your FJR's brake or suspension systems. Or your 'normal' stops are not normal at all.

What lever are you feeling the vibration in? The rear brake? Or the front brake? Are you POSITIVE it is the ABS engaging? To be sure, go do an all out full braking test where you KNOW 100% that the ABS activated so you know what you are looking for.

Something here is not passing the sniff test........

[azitlies]

Not always but more often when coming to a stop it feels like the ABS is engaging on a normal, non-panic stop. Just a little vibration in the lever but enough to know that it's the ABS kicking on. Short of something else is this indicative of wearing/worn pads? I have an '07 bought in '09 with less than 20K miles so I can't imagine the pads being too worn. Is this normal and I'm just getting used to the bike and braking harder now that I've got some miles or something I need to be concerned about?

Something doesn't seem right there. I doubt that even if you're braking harder, that it's so hard the abs should be kicking in. Are you flying up to the stop and getting all over the brakes? I mean emergency stopping?

While the ABS will kick in a little soon, sounds like what you're saying is a lot soon.

Like others have said, check the pads. If they're okay I'd go and actually practice some emergency stopping. You may find it's not the ABS you're feeling. Then again, you may then know it's time to visit the dealer...

[SLK50]

It's simple enough to test if its the ABS: pull the ABS fuse and go for a ride.
If the condition persists, it's NOT the ABS.

I bet it's just low frequency brake squeal. Clean the rotors, rough up
the pads, ( they may be contaminated or glazed ) go for a ride
and see if there is any improvement.

Please get back to us with the results.

[Fred W]

I have noticed (sometimes) a high frequency vibration through the front brake hydraulics. Usually it is best felt when the bike is slowing to a stop (not at high speed). It is definitely not due to any rotor warp-age. Not that frequency.

My take on it is it is the edges of the ventilation holes in the rotor catching the pads. I think it only happens after the chamfer has been worn off o those holes. I have thought (briefly) about re-chamfering those holes but decided it was just nothing to be concerned about instead.

[Jetpilot5]

It's simple enough to test if its the ABS: pull the ABS fuse and go for a ride.
If the condition persists, it's NOT the ABS.

I bet it's just low frequency brake squeal. Clean the rotors, rough up
the pads, ( they may be contaminated or glazed ) go for a ride
and see if there is any improvement.

Please get back to us with the results.

I agree. I get the same thing on occasion. It's discussed pretty well here.

http://www.fjrforum....=1

[escapefjrtist]

Is the feel only there intermittently and does *it* go away if you brake harder? If so, I'll bet my pennies that RCook is feeling the standard FJR floating brake rotor occasional noise, vibration etc., etc...Every FJR I've owned has done this, some to more extent than the others.

When all other suggestions are checked out and you turn up nothing wrong...this is it. I could be wrong though... YMMV

--G

[kaitsdad]

One other thing to check for - warped rotor.

[RCook]

The feeling is in my hand so the front brakes. I'm not panic stopping, or waiting until the last second to brake just a normal stop but I feel what seems to be ABS pulsing. I'll look at the pads and see what I can. I'll admit that I've not done much with brakes on any vehicle aside from my Mtn. bike but that doesn't count really. I don't need to remove the front wheel to make these checks do I? Doing some honest panic stops sounds like a good idea as it pulling the fuse to compare.

Thanks for the suggestions.

[RCook]

It's simple enough to test if its the ABS: pull the ABS fuse and go for a ride.
If the condition persists, it's NOT the ABS.

I bet it's just low frequency brake squeal. Clean the rotors, rough up
the pads, ( they may be contaminated or glazed ) go for a ride
and see if there is any improvement.

Please get back to us with the results.

I agree. I get the same thing on occasion. It's discussed pretty well here.

http://www.fjrforum....=1

That thread describes pretty much exactly what I'm experiencing.

[Harald]

I gotta agree with everyone that you probably don't have an ABS problem and especially not due to pad wear. But pad wear is a good thing to check because you could have at least one of the front pads down to metal by now. You can see most of the pads by carefully looking at various angles around the calipers, but both the left caliper lower pads are almost impossible to see without removing them. And many owners (me included) have found that one of the left lower pads wears MUCH quicker than all the other pads. I've started rotating pads at each front tire change to even out the wear on those expensive pads.

Using an allen wrench to pull the pin in the top center of the caliper allows you to pull the pads up and out of the caliper for detailed inspection or replacement. This is a 5 minute job to pull the pads once you're familiar with the system. If you're gonna replace pads, I'd suggest pulling the whole caliper for thorough cleaning before pushing the pistons back into their bores. Helps the seals last longer.

BTW, a few notes on Gen II brakes:
the right side caliper lower pads are actuated by the rear brake.
stick with OEM pads because they work good, last long and don't accelerate wear on rotors.
Yamaha sells front pads in sets of 2 and you need a total of 4 sets (8 pads) to do all front pads.

[ionbeam]

Not always but more often when coming to a stop it feels like the ABS is engaging on a normal, non-panic stop...

The ABS computer determines when to apply the anti-lock brakes based on 'slip angle' which is a math calculation based on vehicle inertia and deceleration rate. During deceleration, when the chassis has more inertia than the tires have traction it will result in tire skid. The ABS computer recognizes the impending skid and will activate the ABS to prevent tire lockup.

If braking is within normal braking force the ABS computer should never activate ABS action. The primary input for measuring braking force is taken from the rate of change seen in the VSS sensor (Gen I) or the ABS wheel sensor (Gen II).

It is almost certain that what you are feeling is NOT from overly sensitive ABS application.

[wmadoty]

I frequently activate my rear ABS. This seems to be pretty common and does not mean there is anything wrong with the brakes. I down-shift a lot while breaking, and when downshifting I will frequently feel the rear ABS engage. This happens more often in the wet or with poor road surfaces, but it can happen on great road surfaces while breaking normally. The ABS application only lasts for a very short time.

Other bikes I have owned would actually lock up the rear wheel for a very short time while down shifting and breaking. I suspect this is pretty normal.

I have noticed on my bike that it takes a massive effort to engage the front ABS. I did not think it worked because even under very hard breaking I never felt it kick in. I tested it once. It took many attempts to apply the front breaks hard enough to engage the ABS. Unreal how well mannered the bike is when the front ABS is engaged.

[RCook]

Well I got a flashlight and took a look, from what I could tell the pads have plenty of life left so I'm not worried. The bike will be heading to the dealer for a once over here before my big ride in June so I'll mention it then as well.

[LAF]

If it was me I would pull the calipers, remove the brake pads, clean the pistons with toothbrush and brake cleaner. I use wood blocks of various thickness to clamp the pistons on so the do not pop out. I would also sand the rotors a bit and look at them, you can see pad materiel embedded on the rotors, just sand till you see that coming off, brake cleaner is your friend on this job. Sand from the center down not around the circle shape of the rotor.

Then go bed them in. You can find How To Bed in Brakes on any search engine

I do this every tire change myself, and while it is work it is also something drilled into me over the years.

I would suggest you find some gravel on some strait road and really kick in the ABS. That is what I did to "exercise" the ABS unit before doing a brake flush. And I wanted to know what it felt like and I did it quite a few times to know what if felt like.

I could not imagine ABS engagement at stops, I would need to sort that out.

I also like the idea of pad rotation, and that may serve you here sorting it out.