Rear master cylinder failure on 2016?

[Prestone]

Has anyone experienced rear master cylinder failure before? Just over one year of ownership I realized I had all most no stoping power from rear brakes and I couldn't even get it to actuate the abs. I decided to try to swap all the fluids out and see if it improved and no changes. Would this be covered under yes? The front brakes works like they're supposed to. The bike has little over 23,000 miles. Thoughts?

[HotRodZilla]

Take it in for warranty. It should be covered.

[wheatonFJR]

Stupid question: Pads are good?

[Prestone]

I hope so considering how rarely I use them. I'll check after work tomorrow

[raYzerman]

It would be very unusual for a master cylinder failure this early in life...... however, it also can be difficult to judge the rear pedal feel and kick in the ABS by riding. I'd bet there's air in the system, very difficult to remove sometimes. Was the right front lower caliper flushed and bled? Did you cycle the ABS via the diagnostic connector and bleed again? If you press down on the pedal does it fully return (needs lube)? If all that is good, if you press down on the pedal, release and pump again does the pedal seem higher and firmer?

[Prestone]

The reason I was leaning towards master cylinder is becuase the pedal was soft before even opening the brake system for the first time. Like I side originally the reason I even changed the fluid is becuase the pedal was already soft. Pressure does not build when I pump the rear brakes and it never gets firm.

[ionbeam]

If it's under warranty take it to the dealer. If the dealer finds the brakes to be NORMAL, can't find a problem or bled the brakes yet the problem persists then read on.

It seems that all '13 and up FJRs have had a soft rear brake. I haven't seen anyone find anything 'broken' but there have been a lot of How To Bleed Brakes postings. In keeping with the trend, my '15 has a soft rear brake. Not so soft that I can't activate the ABS but it takes a bit more than expected travel & force to get braking action. I've gotten used to it and don't notice it anymore, but then again I don't use the rear brake for serious braking. When I get a chance I will bleed the rear brake SYSTEM (front caliper, ABS metering block and rear caliper) and see if it improves.

I don't think that the inability to pump up the brakes rules out needing to bleed the rear brake system. Back on the olden days of car brake troubleshooting, it used to be suggested to carefully clamp the brake hose(s) and see if the pedal became firm to separate spongy air problems from master cylinder issues. It was also done to determine front brake from rear brake problems. I don't necessarily recommend doing this because it is possible to damage the brake hose when clamping it closed.

After frequently riding in heavy rain this summer my rear brake pivot is showing signs of needing a good cleaning and lube. One probable symptom is my cruise control occasionally being flaky.

Let us know what takes care of your squishy brake issue. (Note the non-use of the word 'problem'.)

[bungie4]

I'm glad that it's only my rear brake that soft. Like Ionbeam, I can activate my ABS through the peddle, but I practically have to stand on it to make it go.

[wheatonFJR]

Here's to hoping you get the rear brake how you like it.
Not that you use it...but just in case.

I had recent chance whilst riding with some hooligans on NC80 to find out my abs does in fact work and work well. Both front and rear...making up for ham handed lever pressures.
EDIT: ...although my rear brake is softer than I would like, it still works as I want it too...I just wish it wasn't linked to the front some times.

[Prestone]

Motorcycle is at the dealership and they have a 100 dollar diagnostic fee. Wtf. I have never heard of this. I'm going to be really pissed when they tell me there is no problem or tell me they had to bleed it but the pedal feels the same. I guess I will have to just wait and see.

[wheatonFJR]

Motorcycle is at the dealership and they have a 100 dollar diagnostic fee. Wtf. I have never heard of this. I'm going to be really pissed when they tell me there is no problem or tell me they had to bleed it but the pedal feels the same. I guess I will have to just wait and see.

That fee should be waived if the part is a warranty part issue. Warranty work is free.

[Prestone]

Well let's hope it's covered. Thanks Wheatie. I just hope they don't try telling me there is air in the system when they pedal was already that soft before I opened the system for the first time.

[Prestone]

Well dealer just called and said no issue with air in lines. Not completely confident in this becuse the service manager was out of town and I dropped it was a bunch of kids in the service area. I guess only time will tell. They didn't charge me the 100 dollars, so that's good I guess.

[kieefjr]

Hmmm, a soft pedal is common??
The weather has just been too cold for me and the couple of warmer days something else came up. Once I get out I’ll engage the ABS.

My soft pedal is the first thing on my new ride I noticed and the previous owner flushed all the fluids so I immediately thought air.
Old trick I’ve used before is clamping or weighting down the pedal overnight, this will sometimes force the air to bleed out.

Putting a dumbbell on the pedal and overnight didn’t work, I saw no air. Just re-bleed the rear but still no air.

Hmmm.

[mcatrophy]

Hmmm, a soft pedal is common??
The weather has just been too cold for me and the couple of warmer days something else came up. Once I get out I’ll engage the ABS.

My soft pedal is the first thing on my new ride I noticed and the previous owner flushed all the fluids so I immediately thought air.
Old trick I’ve used before is clamping or weighting down the pedal overnight, this will sometimes force the air to bleed out.

Putting a dumbbell on the pedal and overnight didn’t work, I saw no air. Just re-bleed the rear but still no air.

Hmmm.

Have you bled the front linked brake? I'm assuming this is a Gen 2 or 3.

[CollingsBob]

I bled the rear/front brakes twice..then I rotated the rear brake lever one spline on the shaft, thereby preloading the system very slightly..

[FJRoss]

Hmmm, a soft pedal is common??
The weather has just been too cold for me and the couple of warmer days something else came up. Once I get out I’ll engage the ABS.

My soft pedal is the first thing on my new ride I noticed and the previous owner flushed all the fluids so I immediately thought air.
Old trick I’ve used before is clamping or weighting down the pedal overnight, this will sometimes force the air to bleed out.

Putting a dumbbell on the pedal and overnight didn’t work, I saw no air. Just re-bleed the rear but still no air.

Hmmm.

Have you bled the front linked brake? I'm assuming this is a Gen 2 or 3.

mcatrophy is right about the linked brake. Make sure you bleed the lower bleeder on the right front caliper (using the rear brake pedal) before bleeding the rear brake caliper. The right front lower piston pair is actuated by the rear brake pedal, not the front brake lever.

[kieefjr]

Thank you! That appears to be it. A lot of air.

Tomorrow looks like a good day to ride my new to me bike for the first time.
I know my reservoir is filled to the max and I will take things apart again to view and re-bleed if needed.

Thanks.

[rbentnail]

I didn't see it- have you manually cycled the ABS with the test connection? I had an air bubble stuck "in there" once long ago. I usually cycle ABS, replace fluid, cycle ABS again. Easy stuff, no special tool. I used a paperclip last time. It's in the FSM & I have a pdf on dropbox adapted from ionbeam's fjrforum post if you need it.

https://www.fjrforum.com/topic/136000-t ... ent-834610