Yeah that seems a bit louder than I recall too, but may be enhanced by the video. How much pulsation is present in the lever? Compare it to the rear brake. It should both vibrate and sound similar.
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Bad ABS hydraulic unit/module 2007A, per Yamaha dealer
- Thread starter rcpd807
- Start date
Help Support Yamaha FJR Motorcycle Forum:
It is as loud in person as it is in the video. The rear brake feels like I would expect it to in reference to pulsation. The front lever very forcefully pushes out and you can feel it pulse, but not as defined as the rear. The sound stay the same for the entire cycle.
Sounds a bit suspicious. Maybe the dealer was right this time?
Colin24
IBA# 446
Just skimmed trough this thread and it seems similar to a problem I had last year (and has started to creep back in again this year).
If the bike sat for a couple days I would go to use the brakes and there would be nothing. I would have to pump the brake lever a couple times to bring the pressure back then it would work.
The problem was not in the master cylinder nor with air in the lines. It was with the calipers on the wheels. This is kinda hard to describe but there are two issues that can cause this that are similar but different.
If you haven't dissassembled and cleaned your calipers in a while spooge can build up on the pins or even the sides of the housing where the pads brush by. When I would pump the brakes it would force the pad against the spooge and the brakes would work. But over time the spooge would push the pad back away from the disc. So if the bike sat for a few days the pads were loose on the disc (for lack of a better way to describe it). Once I would use the brakes a couple times they would make contact so that braking was a single squeeze.
A similar thing can happen with cylinders in the calipers. They can build up a line of spooge that pushes against the rubber seal. Its weak enough that applying the brakes a few times overcomes it. But if left to sit it will apply back pressure pushing the pads away from the disc.
So the fix is fairly straightforward and not nearly so pricey. Take the calipers apart and give everything a very good cleaning. The pins are easy to clean. The pistons are more difficult.
If you suspect its the pistons in the calipers you can by the parts (I think even a rebuild kit with pistons and seals) and rebuild the entire caliper. Messy job but doable. My FJR has 270K Km and I have actually rebuilt the calipers once already (new seals and new pistons). Starting to think its getting time I do it again.
Hope this helps.
- Colin
TownsendsFJR1300
Well-known member
I don't have an FJR shop manual anymore however for my FZ6 Yamaha recommends caliper SEAL REPLACEMENT EVERY TWO YEARS. Someone with a FJR shop manual can check / post the recommendation.
I re-sealed my old 04 fronts when I had it (non-ABS), as the calipers were hanging up badly. The seals get hard, loose pliability and don't like to retract. I also re-sealed the seals on my current 07 FZ as they were beginning to drag excessively.
I've found 4-5 years is the realistic life expectancy of the seals...
Pistons just needed some cleaning on both bikes but no pitting, etc.
For the fronts, put the bike on the CC and lift the front wheel (scissor jack under the header).
Now spin the wheel, by hand as hard as you can. If under .5 - .75 rotations, they need addressing.
My FZ went from about 3/4 a spin to currently (about 3 years later) to about FOUR FULL rotations.
My 04 FJR literally had hot rotors after a road trip with the front brakes NOT USED.
None of this is related to the OPs situation. He is not getting any braking power at the wheel regardless of how many times he pumps the lever.
As for testing and replacing the seals, that is a good test to perform. I try to do it at each tire change so that if there is drag you can clean the caliper pistons at the same time since you'll have it disconnected and in your hand. My old '05 still has its original seals in it, and the pistons are still properly retracting when the lever / pedal is released. YMMV
As for testing and replacing the seals, that is a good test to perform. I try to do it at each tire change so that if there is drag you can clean the caliper pistons at the same time since you'll have it disconnected and in your hand. My old '05 still has its original seals in it, and the pistons are still properly retracting when the lever / pedal is released. YMMV
Actually after I squeeze the lever once, I have braking power for that one stop/maneuver. My rear brakes are fine so I am not sure I have the issue mentioned by Colin24.
Since I have had the bike home I have cycled the ABS module multiple times and used the Mity Vac. I must say my brake lever feels firmer than it did when I got it home. It starts to build pressure as it approaches the grip, where before it would easily go all the way to the grip.
My next move is to remove and install the new master cylinder again, just to make sure everything is fine there.
I can't get past how loud the cycling of the ABS module is, which can be heard in an earlier video I posted.
Thanks for all of the help and suggestions.
RossKean
Well-known member
Just a note on rotors - if they are badly warped, the brake pads will be pushed out further than usual as the wheel turns. This could result in further-than-usual lever movement. Doesn't sound to me like this is the issue but thought I would mention it.
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mcatrophy
Privileged to ride a 2018 FJR1300AS
Not a stupid suggestion, when I had warped rotors (dished, not wavy) it made braking somewhat problematic. After they'd cooled off, all squeezing the lever did was try to straighten the rotor, very little retardation.
TownsendsFJR1300
Well-known member
Plus 1 ^^^^
Pushing a pad just a touch (for what ever reason) will take a full squeeze of the lever BEFORE it does anything...
Just for S&G's, check both disc run-out spec's and rule those out..
+2 - I did not get that the brakes worked fine after a squeeze or two from the initial post. That sounds like a warped rotor pushing the pads back.
The way to test this theory is to squeeze the brakes firm, then leave it for a while and come back and test the brakes again later. If they stay firm when left stationary, but get soft again when the wheel rotates, then check the brake rotors for runout. It could be just one, or both.
The way to test this theory is to squeeze the brakes firm, then leave it for a while and come back and test the brakes again later. If they stay firm when left stationary, but get soft again when the wheel rotates, then check the brake rotors for runout. It could be just one, or both.
Donal
Well-known member
Not sure how cold it is where you are but........
Low temps will not help when trying to get rid of air in a hydraulic system.
The fluid will become more viscous and will not allow bubbles to migrate freely.
When using your Mity Vac the fluid flow will tend to stay in laminar flow when ideally you want turbulent (to flush out any trapped air).
Low temps will not help when trying to get rid of air in a hydraulic system.
The fluid will become more viscous and will not allow bubbles to migrate freely.
When using your Mity Vac the fluid flow will tend to stay in laminar flow when ideally you want turbulent (to flush out any trapped air).
Once I squeeze the brakes firm and walk away for about a minute, when I return I have pull the lever approx 2 times for pressure to build to the level it should be at.
Rotating the wheel or temperature has not had any change to the situation. The same issue exist while actively riding in 90 degree temps.
Based on that, should I look into the rotors?
TownsendsFJR1300
Well-known member
You can look, but that's not the problem then. Only if the rotors are bent, they'd be pushing the pistons back out...
Was there anytime the "over the fender brake line loop" was empty of fluid? (I think they still have it...)
Was there anytime the "over the fender brake line loop" was empty of fluid? (I think they still have it...)
This is starting to look more like air in the hydraulic lines after all.
RossKean
Well-known member
wetwolf
Well-known member
It's a new M/C, so thats prolly not the problem. IMHO, it's STILL air in the lines.
bleed per post # 13 and get 'er done.....
Da Wolf
bleed per post # 13 and get 'er done.....
Da Wolf
I will keep pushing and pumping new fluid in the system.
Possibly worth mentioning.....this issue did not start after right after I changed the fluid or did anything that would introduce air in the system. It just kinda started one day.
How is a 2007 a new motorcycle?
RossKean
Well-known member
I think MC refers to the Master Cylinder that was replaced.
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