Brakes failed

[Ishkatan]

My bike would not accelerate when the RPM was below 3000 rpm in 4th and fifth gear but worked fine if I down shifted and got high rpm. I came to a stop just fine but when I reached for the brake after letting go it collapsed. No pressure front or back. Got in the stopping lane and turned off the bike. Still no brakes. Waited a bit. Turned on the bike to move it up a slope.... and had full brakes. Not trusting to ride it home so still waiting for aaa. They are having problems finding a truck to tow a motorcycle.

 

[RossKean]

Gen I, II or III+?
ABS?

Betting the problem started with a stuck rear brake pedal. Overheated and lost brakes although I am not sure why front and rear...
Look for damaged / warped rotors and cooked brake pads.

 

[Ignacio]

I'm thinking the same thing as RossKean....stuck rear pedal would be my first look not knowing what year it is and details about the model you have.

 

[TooManyBikes]

Feel your pain, and bewilderment about your FJR failing.

Have disks, calipers, ... from my 2012 parts bike if yours are damaged or worry-some. Please PM if I can help you.

 

[SkooterG]

It sounds like you boiled the brake fluid for whatever reason. When the fluid cooled down again your brakes worked again. As suggested above, it sounds like you have a dragging brake pad. After that is figured out, be sure to flush the entire brake system.

 

[Sunnyorlando]

It sounds like you boiled the brake fluid for whatever reason.

Right - the boiling point expand the fluid and pressurizes the brakes. When it cools then it would release the pressure and allow the wheel(s) to turn freely.
However - why front and rear which do not share reservoir? It doesn't seem likely that the cause of the boiling point would be the same for front and rear even with ABS - which we don't know if the one has, and I don't believe the two fluids (F&R) would be affected via the ABS as they don't share common paths. You'd think they the ABS system would have a back pressure control valve. Odd.

 

[RossKean]

Right - the boiling point expand the fluid and pressurizes the brakes. When it cools then it would release the pressure and allow the wheel(s) to turn freely.
However - why front and rear which do not share reservoir? It doesn't seem likely that the cause of the boiling point would be the same for front and rear even with ABS - which we don't know if the one has, and I don't believe the two fluids (F&R) would be affected via the ABS as they don't share common paths. You'd think they the ABS system would have a back pressure control valve. Odd.

I wondered about that as well. Pure speculation, but with the rear brake applied, the lower front piston pair (linked brake) would also be applied and may have overheated the right front caliper causing the fluid there to boil as well. Especially if the fluid was old and had adsorbed a lot of water...

 

[Rocnsanman]

Because the rear AND front lower piston are linked this could well be the problem.
It is very easy to ride with the foot brake applying pressure unaware. Even a little pressure over a distance will boil the brake fluid and the symptoms will be as you described. Check your brake fluid level and don't overfill the reservoir or you'll have other issues. As suggested, check your rotors and pads. Good luck

 

[RiderJoe]

I agree with the previous assessments, as the same happened to me in the past. The only thing that I can’t inagine is why would both (front and back) systems fail at the same time. That was not what I experienced. The OP stated:

I came to a stop just fine but when I reached for the brake after letting go it collapsed. No pressure front or back.

In any case, it is advisable to flush the brake lines and fill with new fluid after an event like that. Slightly sanding the brake pad surfaces may also be a good idea to remove any glazing that might have occurred.

 

[Ishkatan]

This is 2008 1300AE - no clutch, just shift version. What has me puzzled is that the bike came to a stop at a stop sign, and only after I released the brake lever and applied it again did it fail. Then I tried the rear and that was also failing.

The other symptom is that before this, while riding in 5th at 2000 RPM giving it gas did not seem to increase power. It was as if I had not done anything with the throttle. Kicking it down a gear picked up the RPM and suddenly the bike accelerated nicely, particularly when I dropped it into 3rd. But the RPM had to be around 3000 for it to respond correctly.

Also, the front level was collapsing totally. The rear was collapsing, but if I really pressed all the way hard I had a tiny bit - just barely enough to keep the bike from rolling easily. I thought I had a broken brake line but there was no fluid coming out anywhere. The bike had stopped normally. It was only after I rolled forward a little to see traffic and re-applied the front brake, and then the rear, that I realized I had no brakes at all.

Thanks for the comments above about the front calipers dragging. I have not been riding much so it may be that I forgot to watch foot position on the rear brake and was dragging it. However, I have some play in the back brake just to avoid that issue. It still does not make a lot of sense to me since if the rear break is applying pressure to 2 of the front pads it should not be using the front reservoir. ie. the rear pedal has it's own reservoir and when I bled the brakes 2 years ago it was a separate operation for front and rear. I need to look at the schematics to see how the rear applies the front brakes. I thought it was the front that applied pressure to the rear. Might be getting my bikes confused.

The idea of not having any brakes front or rear is scary. A failure like this should never happen, even if you mess up one brake set by burning the pads/rotor or lose a brake line. I am going to look at things later this weekend and then have the Yamaha shop check the bike and prepare for a $1500+ bill. I expect it is the ABS controller (maybe that got affected by the hot brake fluid?) I will have them do a few other things since the only thing I have done on the bike in 10,000 miles is change the oil every season/3000 miles and changed the coolant and brake fluid 2 years (4000 miles) ago. I am at 30,000+ now. Still, I am now wondering if I want to keep a bike that can have both sets of brakes fail at the same time. That is bad engineering. At this point, my smile as I hit 75 on the highway might be a bit tremulous.

P.S. Probably not relevant: For oil changes I used Mobile 1 10w-40 with Mobile 1 filter this spring and last year. Yamaha oil and then Rotella 5 for diesel once in the past. Mobile 1 gives better clutch feel when I twist the throttle and the automatic clutch starts to grab.

 

[RossKean]

I think the most likely scenario is that the rear brake pedal was stuck. This needs to be removed, cleaned and greased at least annually - more frequently if ridden in a lot of rain. The apparent low power in high gears suggests that the brake was, in fact, applied (either through inadvertent application or a stuck pedal). In the Yamaha linked brake system, the front lever applies braking to the two left piston pairs and the upper right piston pair. The rear brake applies to the rear caliper and the front lower right piston pair.

I don't think that this is an inherent flaw in the system - FJR brakes are excellent and very reliable. I have never heard of a simultaneous front and rear failure - or in fact any failure that couldn't be attributed to a stuck pedal, seized slider pins or overfilled reservoir. Far more likely a failure in maintenance - especially since proper function was restored after cooling. I doubt that the ABS controller is at fault...

FWIW, you should have stopped riding immediately when it became clear that there was an issue with power delivery in higher gears - especially when it wasn't a function of clutch slippage. A cursory examination would have revealed the rear brake rotor (and possibly the right front) to be smoking hot!

 

[SkooterG]

When was the last time you flushed and replaced the brake fluid. As it gets older it's boiling point is lowered.

From my understanding. there is no possible way a malfunctioning ABS unit will cause a loss of brakes. Just a loss of the ABS function.

 

[Whooshka]

This is 2008 1300AE - no clutch, just shift version. What has me puzzled is that the bike came to a stop at a stop sign, and only after I released the brake lever and applied it again did it fail. Then I tried the rear and that was also failing.

The other symptom is that before this, while riding in 5th at 2000 RPM giving it gas did not seem to increase power. It was as if I had not done anything with the throttle. Kicking it down a gear picked up the RPM and suddenly the bike accelerated nicely, particularly when I dropped it into 3rd. But the RPM had to be around 3000 for it to respond correctly.

Also, the front level was collapsing totally. The rear was collapsing, but if I really pressed all the way hard I had a tiny bit - just barely enough to keep the bike from rolling easily. I thought I had a broken brake line but there was no fluid coming out anywhere. The bike had stopped normally. It was only after I rolled forward a little to see traffic and re-applied the front brake, and then the rear, that I realized I had no brakes at all.

Thanks for the comments above about the front calipers dragging. I have not been riding much so it may be that I forgot to watch foot position on the rear brake and was dragging it. However, I have some play in the back brake just to avoid that issue. It still does not make a lot of sense to me since if the rear break is applying pressure to 2 of the front pads it should not be using the front reservoir. ie. the rear pedal has it's own reservoir and when I bled the brakes 2 years ago it was a separate operation for front and rear. I need to look at the schematics to see how the rear applies the front brakes. I thought it was the front that applied pressure to the rear. Might be getting my bikes confused.

The idea of not having any brakes front or rear is scary. A failure like this should never happen, even if you mess up one brake set by burning the pads/rotor or lose a brake line. I am going to look at things later this weekend and then have the Yamaha shop check the bike and prepare for a $1500+ bill. I expect it is the ABS controller (maybe that got affected by the hot brake fluid?) I will have them do a few other things since the only thing I have done on the bike in 10,000 miles is change the oil every season/3000 miles and changed the coolant and brake fluid 2 years (4000 miles) ago. I am at 30,000+ now. Still, I am now wondering if I want to keep a bike that can have both sets of brakes fail at the same time. That is bad engineering. At this point, my smile as I hit 75 on the highway might be a bit tremulous.

P.S. Probably not relevant: For oil changes I used Mobile 1 10w-40 with Mobile 1 filter this spring and last year. Yamaha oil and then Rotella 5 for diesel once in the past. Mobile 1 gives better clutch feel when I twist the throttle and the automatic clutch starts to grab.

I'd start by spraying some penetrating fluid on the rear brake linkage and do a proper bleed before setting yourself up to get bent over by a dealer. That may just be all you need. If that works then properly lube the brake pedal assembly.

 

[RossKean]

I'd start by spraying some penetrating fluid on the rear brake linkage and do a proper bleed before setting yourself up to get bent over by a dealer. That may just be all you need. If that works then properly lube the brake pedal assembly.

Penetrating fluid (even WD-40) will loosen it up and can get you going if stuck on the side of the road, but it REALLY needs to be dismantled, cleaned up and greased (as you mentioned).

I do it every season along with clutch lever (especially brass bushing), front brake lever and shift linkage. (The OP has an AE, so the clutch and shift levers aren't a major issue.) I also flush brake and clutch hydraulic fluid every two years.

 

[YankeeFeejer]

Another issue could be sticking pistons. My 2009 did the same thing. I live in Massachusetts and ride in winter. Salt and sand on the roads caused my caliper pistons to not retract after releasing the brake pedal/lever. Took the calipers off cleaned pistons thoroughly and replaced all caliper seals, new brake fluid. Worked fine after that. Good luck

 

[Bounce]

Good Point. Every pad swap I do an inspection and cleaning of the calipers. Every other time (or if needed sooner), I'll even pull the pots and give them a good polish with a fine Scotch Bright pad; inspecting/cleaning the dust boots, etc.

 

[RossKean]

Good Point. Every pad swap I do an inspection and cleaning of the calipers. Every other time (or if needed sooner), I'll even pull the pots and give them a good polish with a fine Scotch Bright pad; inspecting/cleaning the dust boots, etc.

I clean and inspect the calipers anytime I have the wheels off - paying special attention to cleaning and greasing the slider pins and cleaning the retaining clips. Usually extend the pistons and clean the sides, but don't actually pop them out. I "rotate" front brake pads to keep them all wearing similarly. (Especially the lower right linked pair)

 

[Ishkatan]

So I think the rear brake boiling explanation might be on the money. Looking at the disk brake I see discolored spots. I don't think the brake was stuck - I think it was rider error - I think I must have rested my foot on the brake pedal and not realized it. I am developing neuropathy in my feet and while I still have some sensation it is not full sensation. The front disk brake does not show the slight discoloration spots. On the rear, where the rustier stuff is on the inside is a tiny bit lower than the area where the pads contact - i.e. I had plenty of disk left. However, it does look scored.
I confess I don't do a good job cleaning the bike (I'm OCD about the fluids but not the bug splat and looks) so I think I will have the shop check the rear shaft and bearings as well as explain why the Front brake failed if the rear overheated.
Actually, I may sell the bike or trade it - see what the shop diagnoses is. I am still trying to decide if I trust a bike that allows the front brake to fail if the rear has a problem. I don't mind the rear brake applying some pressure to a pair of front calipers but the other front calipers should be independent.

 

[Ishkatan]

BTW, this is my bike. The screen is a Rifle +2 (barn door but great). The white things in front / bottom are home made wind deflectors (idea stolen from my Goldwing using small cutting boards from WalMart.) The crash protectors are nice to have and saved the bike several times from falls when standing still, but can catch the heel of my boot if I push my leg far back.

 

[BigOgre]

What do the pads look like? Also curious if the bike lives outside?