Do I have a brake problem?

[leclairk]

I bought an 06 FJR with 4200 miles last week. When I bought the bike the PO said he had the fluids done including the front and rear brake fluid. In checking the fluid levels the fluid does look new so I believe he had it done. I have never had a bike with ABS so I am not sure what is normal. Going down a mild gravel road I can lock up the back brake and slide the rear tire. Shouldn't ABS prevent this from happening? The other problem I have is that the rear brake is really soft. I can push the rear brake as far down as it will go before I get the bike to stop very well. The rear brake pedel is in the right position so it's not that. Master cylinder bad with 4200 miles? Or air in the brake line? Any input would be appreciated. Thanks

 

[leclairk]

I bought an 06 FJR with 4200 miles last week. When I bought the bike the PO said he had the fluids done including the front and rear brake fluid. In checking the fluid levels the fluid does look new so I believe he had it done. I have never had a bike with ABS so I am not sure what is normal. Going down a mild gravel road I can lock up the back brake and slide the rear tire. Shouldn't ABS prevent this from happening? The other problem I have is that the rear brake is really soft. I can push the rear brake as far down as it will go before I get the bike to stop very well. The rear brake pedel is in the right position so it's not that. Master cylinder bad with 4200 miles? Or air in the brake line? Any input would be appreciated. Thanks

 

[NMRoadRunner]

air in the line will make it soft as you described, three times.

 

[Fred W]

Also, ABS should prevent rear wheel from locking up on gravel.

 

[ionbeam]

Yes, air in the brake line. Since the front and rear brakes are linked you need to bleed both the rear caliper and the front linked caliper.

With a bike that is 7 years old (!) and only 4.2k miles there is a real possibility that the rear ABS spool has frozen. So far we haven't found a way to fix a frozen spool. If that is the case you would be looking for a used ABS metering block because a new block is ~ $900. While a bit fiddly, it is fairly simple to test the ABS system.

 

[bluesdog]

ABS will reduce, but not completely eliminate, rear tire skidding a little on gravel. The real test is if it does so on dry pavement.

Spongy/soft brake sounds like air in the line. The FJR has linked brakes, and the correct procedure has to be followed in order to bleed them

Sequence:

1. Bleed both fronts (right & left),
2. Bleed linked rear (center nipple on right front caliper),
3. Bleed rear.

Use a turkey baster to remove most of the old fluid from the reservoirs, then fill with fresh fluid before you start the bleeding

Keep the level up in the reservoirs as you work.

Hopefully re-doing the bleed will solve your spongy brake

If there's a problem with the ABS, you should be seeing a warning light.

Complete description of ABS diagnostic procedure here

 

[mcatrophy]

If you are going below about 5(?) mph the ABS won't prevent wheel lock-up. Could explain the locking of the wheel if you were going very slowly.

 

[rushes]

It's also possible to roll around on rocks under a tire that isn't locked up and slide a bit.

I love to test ABS on gravel...

 

[lnewlf]

Try to lock the front on gravel- abs should pulse the brake and prevent lockup....does the abs light come on ?

 

[ionbeam]

Try to lock the front on gravel- abs should pulse the brake and prevent lockup....does the abs light come on ?

And if the ABS doesn't work? Hope ya bounce.

mcatrophy does supply an important bit of info, ABS does have a minimum speed at which it stops activating.

FWIW, so far the only reported ABS failures have been with the rear wheel. Either the front has never failed or the people that had the front ABS fail have been unable to post here again

 

[leclairk]

Try to lock the front on gravel- abs should pulse the brake and prevent lockup....does the abs light come on ?

I don't want to try and lock up the front because if my ABS is not working I'm going to end up on the ground.

I have been trying the ABS on gravel at low speed, probably only 5mph, maybe that's why. I guess I need to go faster and try it. I have never had the ABS light come on or felt any pulsing when I have tried the brakes.

What is the linked ratio on the front and rear brakes anyway?

 

[rushes]

*snip*The other problem I have is that the rear brake is really soft. I can push the rear brake as far down as it will go before I get the bike to stop very well.

I'd bleed the system again first. (I bet you'll get bubbles on the front caliper.)

THEN try to figure out the ABS....

 

[RadioHowie]

If the problem is an inoperative ABS pump, as described in Post #6, it will NOT trigger an ABS warning light as speculated upon in Post #7.

Find yourself a stretch of vacant road, head up to about 30mph and stab the rear brake HARD. If the ABS is working, you'll definitely notice the brake pedal vibrating if the ABS is working. If it isn't working, you'll get a lock-up that is easily controlled.

If your ABS is MIA you're SOL unless you've got lots of $$$.

 

[russperry]

Try to lock the front on gravel- abs should pulse the brake and prevent lockup....does the abs light come on ?

Yeah - that sounds like a good way to find out the ABS is no good - intentional front end lock in gravel. The good news is that its an efficient way to check your ABS AND your frame sliders in one brief test.

 

[leclairk]

Thanks everyone for the tips. I love these kind of forums. Mcatrophy was right on the money. Got the bike up to about 10 or 15 miles an hour, slammed on the rear brake as hard as I could and the ABS kicked in! Thank God. That sounds like an expensive fix. Next step will be to bleed the brakes because my rear is soft (the bikes' that is) (actually mine is too). Thanks guys!

 

[HelzBelz]

I am glad you are on the way to fixing your problem.

But now, I have a problem - beer spurt out of my nose as I was reading everyones posts.. you guys are pretty funny dudes.. and I woke the dogs, who woke the kids, but not the wife.

 

[lnewlf]

Try to lock the front on gravel- abs should pulse the brake and prevent lockup....does the abs light come on ?

Yeah - that sounds like a good way to find out the ABS is no good - intentional front end lock in gravel. The good news is that its an efficient way to check your ABS AND your frame sliders in one brief test.

So apparently none of you hosers ever rode dirt

If the dm thing locks..let off ..geez

 

[A41Billy]

Try to lock the front on gravel- abs should pulse the brake and prevent lockup....does the abs light come on ?

Yeah - that sounds like a good way to find out the ABS is no good - intentional front end lock in gravel. The good news is that its an efficient way to check your ABS AND your frame sliders in one brief test.

So apparently none of you hosers ever rode dirt

If the dm thing locks..let off ..geez

On a dirt bike yes. On a 640 lb street bike? Nah.

 

[ionbeam]

...slammed on the rear brake as hard as I could and the ABS kicked in! Thank God...

That's not a bad thing to do a couple of times a year with the REAR brake, the rear brake only. Unless you activate the ABS metering block using the test procedure previously referenced in this thread while bleeding the brakes, the old brake fluid remains trapped in the metering block. By activating the ABS you will move the spool valve and move a small amount of brake fluid out and a small amount of fresh fluid into the spool valve.

Here in New England where I use my FJR for commuting I will never have a problem with old fluid in my ABS metering block. The shitheads drivers offer me ample opportunities to exercise my ABS. I have had both front and rear ABS verified twice in the last two weeks. <Deleted 12 page rant about feckless, clueless, inept, incompetent drivers and the multiplying factor caused by cell phone use.>