ABS & Rear brake issue- Post front caliper rebuild

[WellWell]

Hello experienced wrenches

The front caliper pistons were frozen and needed a puck and seal service. The calipers were disconnected from the lines
and were open for a week . While parts were coming in, all the fluid drained from the master cylinder. After rebuilding and installing the calipers, the front lines were replenished and purged of air.

BUT in this service, the rear brakes captured air and needed purging. After a fluid change and air purge, it appears the rear (not the front) brake does not want to function properly and appears to capture air somewhere in the system even though there in no air bubbles coming out of the exit brake bleed line.

Also the ABS light also flashes and shines when placed in various gears (bike on center stand).. the ABS light has never illuminated during tests while on the center stand

I am speculating that air has been trapped in the ABS pump and needs some type of purging that is not shown in the factory manual. ( if it is, send the page !)

Experience wrenches and good readers, what is the next step?


WW

 

[RossKean]

What year? 2006 Gen II or later?

Common issue in getting the rear circuit working is the linked brake. The lower right front piston pair is bled first using the rear brake pedal/rear fluid reservoir. Otherwise, you won't get all of the air out.

I expect you are aware of this, but I thought I should mention it as a place to start. Also, the ABS in the early Gen II (06 and 07) was not as robust as in later years...

ABS will act up if you are running the bike on the centerstand.

Good luck.

 

[SkooterG]

Yeah, you really need to give us more info. The braking system is different for the different years. You DID properly bleed the front right caliper of the rear brake?

And as far as I know, ALL FJRs will blink the ABS light when the rear wheel is rotating and the front is not.

 

[rbentnail]

For the Gen2, Gen3+ is a little different so we need to know which model year you have. This is saved from a thread here long ago https://www.dropbox.com/scl/fi/uwz7...ey=v6bxqz660fohid6kecnm814jp&st=57a0bmjo&dl=0. Note the statement "Please refer to your FSM for all the details."

 

[Whooshka]

There is a very specific procedure for a proper bleed. And the FJR needs to have it followed to help eliminate any issues.

Bleeding brakes in a nutshell....

1) Left front caliper
2) Right front top bleeder
3) Rear caliper
4) Right front bottom bleeder
5) Exercise the ABS pump by
a) bike on center stand
b) jumper the light blue and black wires on the connector up under the dash panel near the battery
c) Side stand down, bike in gear (I think)
d) turn on key
e) hold the starter button for 4 seconds
f) pull lever and step on pedal at the same time and hold (you'll feel it cycle/pulsate from lever to pedal to lever again until it stops)
e) turn off key
6) Repeat ABS pump again if you want
7) Repeat steps 3 & 4. Remove jumper wire.

And PLEASE.... report back to let us know if this helps.

 

[RossKean]

3) Rear caliper
4) Right front bottom bleeder

I always do the right front bottom before the rear caliper using the rear brake pedal. I don't recall what the manual says but that has always worked for me. Normally, I do the one furthest from the master cylinder first...

 

[Whooshka]

I don't recall what the manual says either right now but this is my cut and paste notes that's always worked for me. I use a Mity-Vac so I don't think it matters what order for those 2. Aren't those 2 linked anyway?

 

[RossKean]

Aren't those 2 linked anyway?

Yes. Just in the habit of doing the one furthest from the master cylinder first. I have never used a Mity-Vac (or Speed Bleeders) for this service - takes me less than an hour to do all four brake bleeders and the clutch and never ended out with a spongy lever or pedal.
(Mity-Vac might be helpful for the OP if he is having trouble getting all the air out of the system after his caliper rebuild.)

 

[SkooterG]

Yes. Just in the habit of doing the one furthest from the master cylinder first. I have never used a Mity-Vac (or Speed Bleeders) for this service - takes me less than an hour to do all four brake bleeders and the clutch and never ended out with a spongy lever or pedal.
(Mity-Vac might be helpful for the OP if he is having trouble getting all the air out of the system after his caliper rebuild.)

Ok, I'll give. How do you bleed the left front brake caliper without a Mity-Vac or Speedbleeders?

 

[RossKean]

What's the problem? My reach is sufficient and the usual "squeeze, loosen bleeder, squeeze the rest of the way, tighten bleeder, release (slowly) and repeat".