Rear Brake has no effect on 08 GenII

[Fred W]

In addition to what has been said - the last time I replaced pucks I did a thorough job of cleaning calipers. Took some brake cleaner and girl friends toothbrush and made a job of it. It's a dirty fucking job but the payoff was huge. Girl friend didn't even notice.

Yeah, and all her friends thought that she looks great!

 

[russperry]

Flush the brake fluids, you should be flushing every year. FYI they are linked so you will need to bleed the right lower caliper.

The right lower caliper in the front is what solved my issue. Same symptom, no rear brake pedal even after pumping nearly a pint of fluid through the rear reservoir and lines. Finally went to the right front caliper and blew out a massive burp of air and voila, rear brake was back. Its not intuitive but it makes sense since they're linked (as previously noted).

 

[RadioHowie]

Once you check out the brakes and clean them up, new fluids, etc. you'll find the rear brake doesn't feel like it does much by itself. At least compared to 'real' linked brakes like a Honda ST or GL which put more juice to the front than the FJR does. Not that it's bad, you need to use the rear in conjunction with the fronts. That said, even though I say 'weak', once you are at speed, I have locked up the rear with a car tire and skidded it for considerable distance............. it just seems weaker at slower speeds (to me).

Wait...WHAT! A Gen II with a dead ABS pump???

Say it ain't so, Joe...say it ain't so!!

And here I thought dead ABS pumps was a Superior Gen I feature!

 

[RadioHowie]

There may be microscopic fauna inhabiting the glycol-based brake fluid, which, naturally, would create an accumulation of methane gas as a life byproduct over a period of time.

Spoiler

Yeah, I'm talking about amoeba farts here...

Fred, would that be "Flatus Amoebus"???

 

[RadioHowie]

Wait, wut? Oil and oil filter annually???!?!
You only ride 3,000 miles a year??!?!?!?!

'Foosh beat me to it.....

 

[bramfrank]

The FJR has a rear brake?

 

[RadioHowie]

The FJR has a rear brake?

In all honestly, not really. I think it's Yamaha's version of a "hill-holder" mechanism. Keeps you from rollin' backasswards when you give your throttle/brake hand a quick rest at a stop.

 

[woodcycl]

Well, shoot ... had the local shop look at it since they could do so before EOB today. They bled the rear brake without any luck. They said the rear master cylinder has to be replaced. Shoot.

 

[RadioHowie]

Well, shoot ... had the local shop look at it since they could do so before EOB today. They bled the rear brake without any luck. They said the rear master cylinder has to be replaced. Shoot.

Your Forum profile doesn't indicate the model year of your FJR (I mean really, "Other or considering FJR"???) but if you've got an '06 or newer and your "local shop" didn't bleed the lower/right-front caliper, then they accomplished nothing, considering the linked brakes on ALL '06 and newer FJRs. I wouldn't believe their "rear master cylinder has to be replaced" line if the bike IS and '06 or newer.

 

[Fred W]

There may be microscopic fauna inhabiting the glycol-based brake fluid, which, naturally, would create an accumulation of methane gas as a life byproduct over a period of time.

Spoiler

Yeah, I'm talking about amoeba farts here...

Fred, would that be "Flatus Amoebus"???

Exactly!

Well, shoot ... had the local shop look at it since they could do so before EOB today. They bled the rear brake without any luck. They said the rear master cylinder has to be replaced. Shoot.

Yeah... Good luck with that. I seriously doubt that the rear master cylinder has gone bad causing your symptoms. I cannot recall anyone ever having a master cylinder go bad on an FJR that resulted in a loss of hydraulic pressure, unless it was pissing brake fluid on the ground.

It would be amusing to hear how they came to that conclusion, probably just that they tried to bleed the brake and it did not fix it, so time to throw some parts at it. It is a big reason why I would never bring my bike to just any local bike shop for mechanical repair. There are a number of so called bike shops around here that I wouldn't let check the air in my tires if they paid me for the privilege.

I'd call them up this morning, tell them to cease and desist, and get my bike back from them ASAP, before they spend all your money not fixing anything.

 

[RaYzerman19]

They probably didn't know to bleed the right front caliper.......... I seriously doubt the master cylinder is pooched. Maybe the rear pedal is sticking which is a simple disassembly, lube and reassembly?

 

[Geezer]

If you are covered by YES and they will do the work under warranty then I guess it's worth letting them try to fix it by replacing the master cylinder, but it is not likely the problem and it will be expensive if you have to pay for it. As many people have said, bleed it thoroughly. Bleed all of the lines. Others have had this problem and a good thorough bleeding solved it.

 

[Bounce]

Brake (and clutch) fluid is hygroscopic (it attracts water). You have to flush both at least every 2 years or water will get into the system enough to impact braking performance and cause corrosion in parts that are very expensive to replace. Yearly's easy enough to do if you have something like a mighty vac for "power assist". It's then a 1 person, 15 minute job.

 

[bwv]

Well, shoot ... had the local shop look at it since they could do so before EOB today. They bled the rear brake without any luck. They said the rear master cylinder has to be replaced. Shoot.

Ask them to speak with the tech, ask the tech if they are aware it is a linked system:

You will likely have one of 3 outcomes...

1. If they look puzzled or ask what you mean.. time to take the bike back and never return to that shop.

2. If they say "I've been working on bikes for 30 years, i know what im doing" leave faster...

3. If they say "Yes sir, your rear master actuates the lower 2 pistons on the right front caliper and the rear caliper, I bled both thouroughly, front first, then the rear, and then tried cycling your abs pump, and it still wont get a pedal, so I would like to take your master cylinder apart to inspect for the problem, and may have to replace it" Then commend them, and let them try it.. and tip them well when it's fixed.

 

[Bokerfork]

You might try replacing the fluids and bleeding the lines.

 

[RadioHowie]

Whadda dummy I am...the thread title describes the bike, so we all know it's on '08 and HAS linked brakes...

So, if the "local shop" didn't bleed the front right caliper AND the rear, then all they accomplished was wasting some DOT 4.

Woodcycle, you need to find out exactly what your shop did and have them explain it to you. Simply bleeding the rear brake isn't gonna take care of a rear brake problem, at least not completely.

 

[SoCalFJR1300]

How's the fluid look in the reservoir for the rear brake? The rear pads ok? Had the rear wheel off recently?

Fluid looks fine

Pads appear to be fine

Rear wheel hasn't been off in a while

Flush the brake fluids, you should be flushing every year. FYI they are linked so you will need to bleed the right lower caliper.

Never knew or realized flushing the brake fluids was an annual thing ... I do the oil and oil filter annually however. Thanks for the tip.

It's not a annual thing that's "required". I'd only change it annualy if i was riding 30,000 miles a year but it's not going to hurt anything if you do it every year, just a little overkill in some cases.

Most people chnage it every 2 or 3 years from what I've experienced, I believe the manual recommends every 2 years.

 

[Fred W]

Never knew or realized flushing the brake fluids was an annual thing ... I do the oil and oil filter annually however. Thanks for the tip.

It's not a annual thing that's "required". I'd only change it annualy if i was riding 30,000 miles a year but it's not going to hurt anything if you do it every year, just a little overkill in some cases.

Most people chnage it every 2 or 3 years from what I've experienced, I believe the manual recommends every 2 years.

Actually, for brake fluid replacement, mileage doesn't matter at all. You could safely keep the same fluid for over 100k miles, so long as you did that in the allotted time frame (1-2 years). The only reason you change brake fluid is to get rid of the water it has absorbed, and that is purely time related, based on exposure to the humidity in the air.

Those who live near the coast, or in the tropics, where relative humidity is apt to be higher would do well to change it annually or bi-annually at most. If you live and ride only in the desert where there is never any humidity you could safely extend those intervals.

The problem is, there is not good way to gauge how much H2O the fluid has absorbed, so we all tend to just do it on a worst case periodicity to be safe.

 

[Donal]

You could always use something like this however, the cost/benefit ratio would be a little out of kilter! For what it costs I always replace my hydraulic fluids yearly.

 

[RadioHowie]

Someone again please explain to me how brake fluid in a closed system gets exposed to moisture-filled air...

I mean, really, if the brake sysem is open to the air to absorb humidity, wouldn't the system constantly be squirting brake fluid out of the opening every time you used the brakes???