I have a 2007 FJR with 115000 miles. My rear brakes slowly start to engage while riding without pressing the brakes. Ran it through multiple times of test of the ABS PUMP in diagnostic mode and bled the brakes multiple times. Yet once you start down the road it slowly engages. Either release the pressure at the rear caliper brake line or pump the rear brake hard for it to release. And there is no ABS light on. Is there a way to just turn off the abs or remove it. Is there anyway to diagnose if it is the pump, a relay or anything else? A new pump is $2k. about half the price of what the bike is worth. The 2006 and 2007 share the same part number and price, yet the 2008 is a diferent part number and is less expensive and also used ones are available. And are they repairable, if that is the issue? I have a mechanic that is stumped. Pulled the rear brake master cylinder and it is fine, checked the rear brake caliper and it is good, bothe received new seals about 9 months ago with no issues. Any help would be appreciated.
ABS rear brakes engaging
- Thread starter CGS
- Start date
Help Support Yamaha FJR Motorcycle Forum:
RossKean
Well-known member
First thing is to make sure the brake pedal pivot isn't gummed up. Remove, clean and lube.
Second is to make sure the rear reservoir is not overfilled.
'08+ is an improved system but, AFAIK, won't work in the '07. Never heard of a successful ABS pump repair. Almost sounds like a sticking check valve or blocked orifice/brake line. Encouraging that it appears to function in diagnostic mode. Does the ABS work when testing on a slippery surface (wet or sandy road)?
Only other thing I can think of might be to replace master cylinder parts (again) as well as caliper seals etc...
Good luck.
Second is to make sure the rear reservoir is not overfilled.
'08+ is an improved system but, AFAIK, won't work in the '07. Never heard of a successful ABS pump repair. Almost sounds like a sticking check valve or blocked orifice/brake line. Encouraging that it appears to function in diagnostic mode. Does the ABS work when testing on a slippery surface (wet or sandy road)?
Only other thing I can think of might be to replace master cylinder parts (again) as well as caliper seals etc...
Good luck.
Thanks for the insight, but replacing parts that have worked for 6months doubtful it is the solution. Plus neither would just suddenly engage without pressing any brake levors. As for testing, its kinda hard to do when the rear brake begins to engage prior to taking it down a slippery surface.
What Ross said... disassemble, clean and lube the brake lever and it's hardware. Ensure the pedal return spring is good. And a FULL, thorough flush including ABS pump.
My mechanic and I have gone over all the obvious issues. Many times over. I whish it was something simple as a dirty caliper pin or brake cylinder or grungy brake lever. The question is anyway of testing to see if the ABS would suddenly apply pressure to the rear brake. Sorry but my frustration has been going for over 2 months. Of course Yamaha Dealerships will not touch a bike over 10 yrs old and there seems to be no answer but simple steps that have been repeated over and over again. Best bet is throw a bunch of parts at it or get ride of it.
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Do you have new boots with bigger, stiffer toes? I just adjusted my shift lever position to accommodate bigger toes on some new boots. It could interfere with the brake pedal also. Did you ever take the brake pedal off? It can be installed in a number of positions and if it's up too high, your toe could touch it.
You never said whether or not you serviced the brake pedal pivot. But you also never said whether, once the rear brake begins to engage, it continues to engage to the point that it stops the bike. That would be indicative of some seriously strange as well as dangerous behavior. If that's so, I can understand why you would believe the ABS pump is activating the rear brake.
You never said whether or not you serviced the brake pedal pivot. But you also never said whether, once the rear brake begins to engage, it continues to engage to the point that it stops the bike. That would be indicative of some seriously strange as well as dangerous behavior. If that's so, I can understand why you would believe the ABS pump is activating the rear brake.
So I'm guessing you did not disassemble, clean and lube the brake lever and it's hardware. Or check the fluid level. Or acknowledge a FULL THOROUGH flush, by the proper procedure?
You're asking for help but not acknowledging if you've done the things suggested. Did you try accelerating up to about 30-40 MPH and stomp on the rear pedal hard to engage the ABS?
I could list the things I did, but it is all the obvious suspects of what may cause it. I am 100% sure it is not something obvious. I rebuilt the rear master cylinder which means disconnecting it from the brake pedal. It worked fine for 4 months. Did about 10 over 250 mile trips on it with no issues. I am about to just give up which seems as though my mechanic is feeling also. Sell it for parts. No support from dealerships cause of the age. Ridiculous that you can find 10 motorcycle mechanics and 8 out of 10 only work on a Harley.
I'm done.
I have completly remove the rear brake lever assemply because in order to rebuild the master cylinder it is what has to be done, with that I definitly lost fluid and with that I lost pressure so in turn yes I bled the system. While bleeding the system i appropriatly added fluid, OH the correct type Dot 4, then proceded the sequence of rear then front then rear. Lever is GooD! So your guess is not valid here.
And ran the ABS Pump through the proper way of the jumper in diagnostics, not going down the road and slamming the brakes. Not needed anyway WHEN THE DARN BRAKES ARE ALREADY ENGAGING BEFORE I EVEN FOR MY LITTLE TOE ON THE DARN LEVER. After it rest for 10 minutes it releases. Now what is your guess?
My guess is somebody else will help you.
rbentnail
Economic Plankton
It sounds to me like, regardless of what you've done, you still have air in the system. The system heats a little, the air expands and the brakes engage. I'd be looking at alternate direction bleeding and checking returns back to the reservoir. Maybe even a faulty diaphragm .
Thank you, I was told by my mechanic that what he may try Monday. It has us both stumped.
torch
Well-known member
Failing (delaminating) rubber brake lines can have similar effects. Air trapped in the delaminated section cannot be flushed and heat expands it, causing an increase in line pressure. Pressure will drop when the line cools, so brakes release after some time.
graytaz
Well-known member
What he said! They also can create their own check valve stopping fluid from returning. More common with cars.
Don’t know about delaminating brake lines but I do have experience with delaminating hydraulic lines on cranes. The phenomenon can cause all kinds of havoc - especially when loose bits of inner lining start getting lodged in places where they can create restrictions/blockages or act like unwanted check valves.
Granted, you’re not dealing with 3,000+ psi or measuring flow in gallons/minute but torch’s suggestion seems quite plausible coupled with the heating and expansion of trapped air in lines that cannot be thoroughly flushed.
Even if reverse flushing gives you a favorable result, you might still be masking the “true” problem so I’d place my vote on replacing the lines on a 17 yr old bike with that many miles.
But if you DO end up parting out the old girl, let me know. I need some body parts for my ‘07.
Granted, you’re not dealing with 3,000+ psi or measuring flow in gallons/minute but torch’s suggestion seems quite plausible coupled with the heating and expansion of trapped air in lines that cannot be thoroughly flushed.
Even if reverse flushing gives you a favorable result, you might still be masking the “true” problem so I’d place my vote on replacing the lines on a 17 yr old bike with that many miles.
But if you DO end up parting out the old girl, let me know. I need some body parts for my ‘07.
Mihalis fjr
Well-known member
Unfortunately the problem is inside the unit"Stucked valves"Caused if you don't change often the fluids every one or two years and if you don't activate often the unit by your self on a slippery road carefully.
Repairable here with lifetime warranty:Read the description..:
Email them for more info..
https://diag-engine.com/abs-pump-motorcycle/yamaha/2467-fjr-1300.html
Or here:
https://absstuurapparaten.nl/?make=289&model=565&year_id=652&post_type=product&action=vpf-search
Or here:
https://controlunits.co.uk/5d0-8593...00-fjr-1300-abs-hydraulic-valve-block-repair/
Repairable here with lifetime warranty:Read the description..:
Email them for more info..
https://diag-engine.com/abs-pump-motorcycle/yamaha/2467-fjr-1300.html
Or here:
https://absstuurapparaten.nl/?make=289&model=565&year_id=652&post_type=product&action=vpf-search
Or here:
https://controlunits.co.uk/5d0-8593...00-fjr-1300-abs-hydraulic-valve-block-repair/
Last edited:
I just replaced my lines with SS Galfer's. You pay shipping, and you can have my old ones. 06 18K. Probably cost about $15 USD
Pete-o
Pete-o
