Gen III: Rear brake pedal went low

So, I had an interesting thing happen yesterday. I have never experienced this before and I am not sure exactly what to think at this moment.... Here is the story.

2015 ES model with 11,000 miles.

I am on the return leg from a 350 mile trip and had been riding for approximately 1 hour 20 minutes at 75+mph in 100 degree temps. It was dam hot. When I went to pull off the road on to a side road, I applied brakes and the rear brake pedal went very low and barely grabbed, front felt normal and one quick pump on the foot brake and it came back to normal. I then rechecked it several times and no problem, worked great. Bike then sat outside for an hour shortly after that in the direct sun, and again, everything worked normally. I even did a couple of panic stops just to be sure.

Experience tells me and what it felt like was possibly the fluid in the brake line may have boiled? Has anybody experienced this before. Brakes have never been worked on and the only other time I noticed something was after my tires were replaced, they rolled it right out to me and when first applied the front brakes barely grabbed and lever pulled way in. I attributed this to the calipers not getting pumped back up prior, as it has never been a problem. Rear brake was fine btw.

I see no leaks and the fluid level is good.

Oh' and I did a search on this forum and came up empty, so if this has already been addressed please just point me in the right direction.

Thanks,

Fred

WHS said:

Oh' and I did a search on this forum and came up empty, so if this has already been addressed please just point me in the right direction.

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<broken record>What specifically did you try searching on? Thank you.</broken record>

For example, did you try spongy and see the threads about ABS diagnostics, stuck, and others?

Bleed your back brake Fred. Begin with the front RH caliper (lower bleeder) and then move to the rear caliper. Odds are you'll find air in the front caliper...not unheard of if you've never touched the brakes.

--G

Thank you for the response G. I am going to add this to my maintenance list as I have an oil change coming up... However, as of now the brakes are working perfectly, but also not something I want to just ignore either.

And ignacio, you are one of the reasons I am starting to really dislike this forum. Too many snarky responses to questions. Seriously, I don't understand why some people even respond to a query if it's that upsetting to you... just ignore it and move on. I am really starting to understand why people on other sites talk bad about the FJRFORUM...

"if it's that upsetting to you... just ignore it and move on"

+1

Guys, he runs the place, it wouldn't exist without him, and he has every right to roll his eyes about an "empty" search for a subject that's all over the board and has been for years.

As to the problem, your brake pedal is sticking. Widely known issue. As the pivot bushing gets gummed up and the pedal doesn't come back up all the way. The result is slight pressure on the rear rotor, not enough to drag the bike, but enough to heat it up and boil the fluid. Once the bike sits a while, the fluid cools and the brake works fine.

Both the brake pedal and the shifter could use a god cleaning every few months, especially after being out in some weather.

Fred,

You have been given some good advice on what to check/do. I am sure those brakes will be fine afterwards. Be careful of that DOT4 brake fluid, its tuff on paint.

BTW, I like to use external search engines to search for topics on this and other forums. Seems I get better and more results that way. Probably my ineptness here, but that external approach works better for me.

For example, if you used google and searched for: fjrforum.com "rear brake" (use the quotes to force the search on that exact phrase), you will get a great deal of rear brake information, issues, fixes, not only from this forum but from others. Maybe you already do this, but just thought I would throw it out.

Lowcountry Joe said:

Fred,You have been given some good advice on what to check/do. I am sure those brakes will be fine afterwards. Be careful of that DOT4 brake fluid, its tuff on paint.

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Keep a bottle of drugstore isopropyl alcohol near with lid loosened. If you get glycol DOT brake fluid on anything the quicker you can splash rubbing alcohol on it the lesser the damage. Pay special attention to your fingertips which can etch yor fingerprints in embarrassing places.

Thank you all for the advise, I do appreciate it. And Joe, I am well versed in DOT 4 as I spent 25 years in the service business... That and I spilled half a bottle on a Snapper mower once, lol!

And just to be clear, I did do a search and what I was finding did not relate to my issue, at least not in the manner in which I searched. So I posted a query and even stated in my query that if I missed it, please point me in the right direction. I honestly never would have thought to search for sticking brakes, or ABS diagnostics, because that was not how I experienced the issue! Brakes did not stick and no I had no ABS light. This is my first FJR, I have only been a member for a little over a year and sorry, but I am just not as versed as some of you all on the idiosyncrasies of the FJR. So, while these issues may be "widely known" to some of you, it is not to everyone... Now as a result, I have learned something and maybe I can pass that information on to the next new guy. At least that is how I have used the different forums I am a member of. So thanks again, I really appreciate the help!

WHS, "sticking brakes" were mentioned because the rear brake pedal has a tendency to get gummy. Then it sticks slightly on and heats up the rear rotor. That boils the fluid and poof, no rear brake. Usually doesn't affect the front caliper because there is a pressure threshold before the rear pedal activates the front caliper.

Just things to try. Really, except for some kind of weird ABS issue, the brakes are pretty straight forward. A bleed and a cleaning should have you back to normal. Do not forget that the rear reservoir is behind the right hand silver panel under the seat.

If you suspect that the fluid has boiled you can always check if the calipers are very, very hot.

That's where any boiling will occur -- where heat is generated.

You can also check if the brake pedal is moving freely.

I wonder if the cruise control will engage if the brake pedal is down at all? Are there two switches connected to the pedal?

Constant Mesh said:

If you suspect that the fluid has boiled you can always check if the calipers are very, very hot.
That's where any boiling will occur -- where heat is generated.

You can also check if the brake pedal is moving freely.

I wonder if the cruise control will engage if the brake pedal is down at all? Are there two switches connected to the pedal?

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Two sets of contacts, as there are for the front brake switch.