FJR1300 ABS break bleed

[montaseri]

Hello again boys and girls. (remember not to grow up, cause it is a trap)

My 2014 FJR 1300 rear break seems to require bleeding.

Symptoms: I currently have to pump it a few times before it engages, then after a few minutes (5 min), it goes soft again.

I checked the rear break reservoir (under the side panel) and it was just a bit under MAX marker. So break fluid level is good.

This bike is equipped with ABS. I have watched a few videos and now I am confused. I have a fair understanding of bleeding concepts, have done it on my cars, but my doubt is whether the ABS introduces a spin into this or not. On one how-to video, presenter talked about putting the bike in Test Mode (via a jumper around battery bay), presumably to prevent the ABS/ECU from modulating the flow, but that was for "flushing the entire break system", not just bleeding.

I guess my question is -- since I am only doing the rear break (foot pedal) and knowing that foot pedal actually engages both rear and front, then is the following correct ?
1- Remove side panel to gain access to rear break reservoir and open the cap
2- Bleed the farthest caliper first , ie front break first.
3- Loosen the bleeder valve , pump front break, fasten bleeder valve, repeat until no air gap (bubbles) are seen, refill the reservoir if needed.
4- Do step 3 for rear calipers.

Note there is no fuss about any ABS, like it did not exist. Is this it or I need to do something with ABS ECU etc.

Thanks
Medi

 

[cheez]

My practice with my FJR has been to bleed it as you describe, actuate the ABS via hard braking, and repeat. My understanding is that the "Test Mode" jumper forces the ABS pump to actuate, which does the same thing as hard braking, pushing any air bubbles in the ABS system out.

I'm not a mechanic but this has worked for me.

I also recommend the fluid flush, not just bleed, if you're seeing softness. I had similar problems (heat related braking pressure loss) that went away with new fluid.

 

[dravnx]

Actuating the ABS allows you to flush all the fluid out of the system. There are no air bubbles in the ABS. The procedure is to flush the system, actuate the ABS system and then flush again. This insures there is no old fluid in the ABS pump.
I have the jumper and it works on my 2015. I don't know what other years it works on but you're welcome to borrow it. It's also a simple matter to use a paper clip to jump the 2 pins in the connector to accomplish the same thing.
Your bleed process is correct.
My rear brake does the same thing. I bleed it about once a year when it starts getting soft.

 

[montaseri]

My understanding is that the "Test Mode" jumper forces the ABS pump to actuate, which does the same thing as hard braking,

Thanks...note I am trying to understand what you are sharing with me, I am not trying to counter it ... with that said -- it seems to me that the Test Mode in fact DOES NOT actuate the ABS pump. i.e the ECU says if in TEST MODE, then do not modulate (ie on-off-on-off ), basically ignoring what the speed sensor is reporting and only follow the old rule of pass the fluid down the line from reservoir to caliper.

Aside from this principle of ABS ... if I only and only wanted to bleed the lines (no flush), do I need to use the special jumper ?

 

[cheez]

Thanks...note I am trying to understand what you are sharing with me, I am not trying to counter it ... with that said -- it seems to me that the Test Mode in fact DOES NOT actuate the ABS pump. i.e the ECU says if in TEST MODE, then do not modulate (ie on-off-on-off ), basically ignoring what the speed sensor is reporting and only follow the old rule of pass the fluid down the line from reservoir to caliper.

Aside from this principle of ABS ... if I only and only wanted to bleed the lines (no flush), do I need to use the special jumper ?

Dunno boss- I haven't used the test mode thing, so only know secondhand data. Seems like @dravnx has firsthand knowledge with the jumper and can explain exactly how it works.

This looks like a useful reference: https://www.dropbox.com/s/30u7d9l6aoky20q/ABS System Test FJR1300 A.pdf?dl=0

 

[bergmen]

I had the same thing happen to my 2014 FJR (soft rear brake). I ended up doing a bleed of the rear brake system.

BTW, the lower front right caliper is actuated by the rear brake pedal (Unified Brake System) and must be bled first, then the rear caliper.

In my case I found a small bubble of air in the system (about the size of a BB, maybe a bit larger). This cleared up the soft pedal. I have no idea how it got there, I had not done anything to induce it. Changed brake/clutch fluid a few months after and still have a solid pedal.

I did not do anything with the ABS system during both operations.

Dan

 

[montaseri]

I did not do anything with the ABS system during both operations.

Dan

I like that ... thanks

 

[montaseri]

Thanks everyone.
I followed the steps outlined in my original post without any ABS jumper stuff and it worked. Again this was just a bleeding maintenance and not a flush.