Rear Brake Caliper Assembly

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MotoMike

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I need to replace the rear brake caliper assembly on my 2007 FJR1300A.
For which years and models are these assemblies interchangeable? Do I need to look for one specifically for the year and model of my bike?
 

RossKean

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MotoMike

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I was removing the pins so that I could inspect and clean the pads and piston. It was difficult to get the pins moving and I was thinking about squirting on some "Liquid Wrench" penetrating oil figuring they were seized up with rust (even though there wasn't any evidence of that, externally). However, with just a little more torque, the pins started moving, albeit with a lot of resistance, similar to what you would feel if whoever (the PO, not me) had used threadlock on the pins when assembling the caliper. When the pin came out, I noticed "silver threadlock" on the pin. Huh. I never heard of "silver threadlock". Exactly the same thing happened with the second pin. When I inspected the caliper, I saw that the "silver threadlock" was actually the threads from the caliper that had bonded to the threads on the pin and had stripped out with the pins.
 

RossKean

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You might get away with a Helicoil or TimeSert repair if you can't find a decent used part. The new price for the entire assembly was cheaper than I expected but why pay for it if you don't have to. I have seen corroded pistons on calipers so look out for that if you are buying used... If it is an issue, you could probably re-use the piston from your caliper.

I typically use just a touch of antiseize on the threads of the pins - both front and rear brakes. Other than the first removal, I haven't had any issues. (They let go with a "snap" and a fair amount of effort the first time, but without any damage.)
 

MotoMike

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RossKean,
Thanks for the suggestion of using a Helicoil or Timesert repair. I had never heard of either of them. Unfortunately, I have already bought a used (2012) brake assembly on eBay. Had I known about the Helicoil or the Timesert, I would have tried one of those before buying a brake assembly. I will definitely keep that option in mind. In fact, I will go out and buy a Helicoil kit and try it on the ruined caliper assembly, for practice. I will also definitely use antiseize on the "new" pin threads!
 

MotoMike

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I have received and mounted the "new-to-me" brake caliper on my bike. They were from a 2012 FJR 1300. Everything, including the pistons were in good shape. The brake caliper was, of course, free of any brake fluid.

I flushed the entire system, raising the caliper above the brake reservoir and rotating the brake caliper so that the bleed nipple was uppermost in the system. I am positive that no air was entrained from the brake reservoir. There were no bubbles exiting from the bleed nipple when I was done. I then mounted the brake shoes and rear caliper on the holder and I pumped the brake to get the shoes to contact the rotor. I went on to test the brake while the bike was on the center stand and the transmission in neutral. The pedal moved freely and the tire rotation stopped with minimal movement of the brake pedal. I could detect no leaking of brake fluid. Pressing the foot pedal did activate the right lower piston on the front brake.

However, when I did my test ride, I found that I needed to apply significant pressure to the rear brake pedal to slow the bike and bring it to a stop. I am not feeling any "sponginess".

I should mention that I have been in the habit of using my front brake almost exclusively, so I don't really know what using only the back brake feels like.

So: Is what I found duriing my test ride normal, or does it indicate that there is still air in the system. If so, is there any advice regarding how to get that final bit of air out of the system?

Did I miss any other possible causes of why the rear brake needs significant pressure on the pedal to slow and stop the bike?
 

mcatrophy

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I have received and mounted the "new-to-me" brake caliper on my bike. They were from a 2012 FJR 1300. Everything, including the pistons were in good shape. The brake caliper was, of course, free of any brake fluid.

I flushed the entire system, raising the caliper above the brake reservoir and rotating the brake caliper so that the bleed nipple was uppermost in the system. I am positive that no air was entrained from the brake reservoir. There were no bubbles exiting from the bleed nipple when I was done. I then mounted the brake shoes and rear caliper on the holder and I pumped the brake to get the shoes to contact the rotor. I went on to test the brake while the bike was on the center stand and the transmission in neutral. The pedal moved freely and the tire rotation stopped with minimal movement of the brake pedal. I could detect no leaking of brake fluid. Pressing the foot pedal did activate the right lower piston on the front brake.

However, when I did my test ride, I found that I needed to apply significant pressure to the rear brake pedal to slow the bike and bring it to a stop. I am not feeling any "sponginess".

I should mention that I have been in the habit of using my front brake almost exclusively, so I don't really know what using only the back brake feels like.

So: Is what I found duriing my test ride normal, or does it indicate that there is still air in the system. If so, is there any advice regarding how to get that final bit of air out of the system?

Did I miss any other possible causes of why the rear brake needs significant pressure on the pedal to slow and stop the bike?
Two questions, did you bleed that front calliper, and can you get sufficient pedal pressure to activate the rear ABS?
 

RossKean

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...did you bleed that front calliper...
Yep. Front right caliper has two bleed nipples. The upper piston pair is actuated by the front brake lever but the lower piston pair is linked to the rear brake and has to be bled using the rear brake pedal. You should do that one and then re-bleed the rear caliper. You sometimes have to chase the bubbles a bit. It should take very little movement of the rear brake pedal to get solid braking action.

As mcatrophy said, do a test to make sure that you can easily get sufficient braking to activate the rear ABS when riding. Find a piece of traffic-free asphalt - ideally with a little sand on it.

Your rear brake pads could be "glazed" or contaminated. See if a few hard stops helps. If not (and re-bleeding doesn't help), you may want to remove and scuff up the pads with some coarse carbide paper. Wipe the rotor down with some brake cleaner on a clean cloth.
 

Oldjeep

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There is a whole procedure for bleeding the abs. You can't just try to bleed the front and rear lines once you crack the system open
 

RossKean

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There is a whole procedure for bleeding the abs. You can't just try to bleed the front and rear lines once you crack the system open
If careful in the switch, there is no reason why major amounts of air should get into the system. The caliper itself will be dry (unless prefilled on the bench) but the rest of the system could be kept full of fluid. I agree that if a bunch of air gets in and all the way back to the ABS pump then it is more complicated.
 

MotoMike

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Two questions, did you bleed that front calliper, and can you get sufficient pedal pressure to activate the rear ABS?
Yes, I did bleed the lower piston on the right front caliper using the lower nipple and the rear brake pedal.
No, I did not manage to engage the ABS system during my test ride. I will go out and do that today.
 

MotoMike

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Yep. Front right caliper has two bleed nipples. The upper piston pair is actuated by the front brake lever but the lower piston pair is linked to the rear brake and has to be bled using the rear brake pedal. You should do that one and then re-bleed the rear caliper. You sometimes have to chase the bubbles a bit. It should take very little movement of the rear brake pedal to get solid braking action.

As mcatrophy said, do a test to make sure that you can easily get sufficient braking to activate the rear ABS when riding. Find a piece of traffic-free asphalt - ideally with a little sand on it.

Your rear brake pads could be "glazed" or contaminated. See if a few hard stops helps. If not (and re-bleeding doesn't help), you may want to remove and scuff up the pads with some coarse carbide paper. Wipe the rotor down with some brake cleaner on a clean cloth.
Thanks RossKean,
Between your and mcatrophy's suggestions, I will go out and try to activate the rear ABS. If I get no joy with that, I will wipe the rotor down with brake fluid and see how that goes. Finally, I will remove the rear brake pads and give them a light sanding.
Results to follow.
 

Mesing6

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Thanks RossKean,
Between your and mcatrophy's suggestions, I will go out and try to activate the rear ABS. If I get no joy with that, I will wipe the rotor down with brake fluid and see how that goes. Finally, I will remove the rear brake pads and give them a light sanding.
Results to follow.
Do not wipe the rotor with brake fluid.. wipe with brake cleaner
 

Oldjeep

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Yes, I did bleed the lower piston on the right front caliper using the lower nipple and the rear brake pedal.
No, I did not manage to engage the ABS system during my test ride. I will go out and do that today.
Don't engage it riding. Use the test jumper as part of the documented bleeding process.
 

mcatrophy

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Don't engage it riding. Use the test jumper as part of the documented bleeding process.
The riding test is the proof that pedal to brake is functioning, it's not to test the ABS. If the bike didn’t have ABS, I would have suggested ensuring the pedal could lock the wheel.
 

RossKean

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Don't engage it riding. Use the test jumper as part of the documented bleeding process.
Edit: mcatrophy was replying while I was composing...

The point of engaging while riding is to make sure that the brakes actually are working as intended. If the ABS doesn't activate it means one of three things:

1) There is insufficient braking power in the rear brake circuit to lock the wheel and activate ABS.
2) There is something wrong with the ABS.
3) The rider was too timid to apply the brake hard enough and at sufficient speed to activate ABS. :p

The ABS test jumper procedure is suitable to make sure that the ABS is mechanically and electrically functional. Especially useful when you bleed brakes to get old fluid moved through the system. It doesn't tell whether there is sufficient braking action and does not test the simple mechanical braking system.

FWIW, I used the ABS jumper for the first time after a dozen years and almost 300,000 miles of FJR ownership when I refreshed hydraulic fluid last week. I usually just go out and "exercise" the ABS with a few hard stops on a sandy parking lot. Even if you do use the jumper for bleeding, it is a good idea to practice with the ABS every now and then. Helps to know what to expect in an emergency braking situation.
 
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MotoMike

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Thanks to everybody for all your great suggestions. I decided to do the easiest suggestion first. I cleaned the rotor with brake cleaner and immediately noticed the rear brake "grabbed" much better even just at the end of my driveway. I rode to a local empty parking lot that had a nice strip of sand and gravel on it. The ABS engaged easily. So: Problem solved. I am amazed at the difference that came with just cleaning the rotor!
 

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