Rear caliper locked up when braking hard. now rear doesn't work, 2007 FJR

[snyderej]

Coming home the other day I was filtering and had to hit my brakes hard for someone changing lanes without looking first for the random motorcycle (usually an out of state person). As a side note, if you have never filtered like we do here in California, I assure you, it is the safest way to ride. The traffic here in northern CA is so bad, it makes Atlanta look like an easy commute and I moved from Atlanta thinking that was the worst place for traffic.. ever... The difference is here I just ignore the 5 mile standstill and ride the middle. Anyway, I hit my brakes once in Atlanta and the rear locked up (not totally, more like I was pressing it and it was slowing the bike down but I wasn't). I began pressing it on and off and after a couple tries it freed up, almost like a pebble got stuck in the rear caliper piston then fell out. No problems for 1-1.5 years (this is secondary bike), then I slammed on the brakes due to the lane changer and it did it again, I tried the rear brake on off routine and after no success and a dragging rear brake I found the first exit and got off. Lucky it was my exit so after an hour sitting the glowing red disc was normal temp and the caliper seemed to be loose again so I headed home. I quickly discovered I had no rear brake and the fronts seemed spongy. I tried bleeding it but no fluid except a small amount that drained by itself initially came out. I then took the rear caliper off the bike and tried pressing the rear brake but no matter how hard I pressed nothing came out. It's like the fluid is not making it through the unit that sends some of the fluid up to the front caliper and to the rear, like it's blocked or not allowing fluid to travel to the rear caliper. I get NO fluid no matter how hard I press down on the rear brake, reservoir is full. I can kinda tell the rear brake arm isn't traveling as far as it would normally (it does move, just feels like it stops sooner, like the fluid has nowhere to go) travel so that kinda jives with no fluid coming out of the brake line. Has anyone seen this and what resolved it? It's not the caliper, it's gotta be the cylinder or the controller thing, whatever that is called. Let me know if you can help me out.

 

[Queensland Ken]

The only thing I can suggest is to run an ABS diagnostic, plenty of info "how to" on this site.

May well be the solenoid block $$$$$$$$

 

[Geezer]

Is it possible that the bleed nipple is clogged? Try removing the nipple completely and see if you can get fluid to flow. If that doesn't help, then remove the brake line from the caliper and see if you can get fluid out of the brake line to isolate the issue to the caliper.

The fact that the pads dragged after hard use is most likely caused by dirt around the pistons of the caliper.

 

[RaYzerman19]

I recall reading a thread in the not too distant past where the ABS system was clogged. If you check the FSM, General Information, it describes how it works and has a system diagram. What happens (I think) is that fluid sits in the one circuit that only gets fluid movement if ABS is activated. Over time, perhaps that little valve gets stuck (there is a possibility of another spool valve issue) from lack of use. So, yes, cycle the ABS system, it seems especially on '06-'07. The system for other years is slightly different. If you have a stuck valve, look for a used ABS motor/system on ebay, might cost you $200, but beats the OEM price of a new one.

https://www.fjrforum.com/forum//index.php/topic/136000-test-and-maintain-your-abs-system/

As Geezer said, check other things first, like clogged nipples and if fluid is flowing at the banjo bolts holding the hoses to the calipers...... Then, cycle the ABS........ If no cure, work your way back by loosening banjos until you find the blockage point...... hopefully you don't get back to the ABS unit.

 

[RossKean]

As suggested, start loosening fittings and see when or if you get fluid flow. If you don't get flow before the ABS block then perhaps you have a problem with the rear master cylinder - rebuild or replace. There is no reason that the front brakes should feel spongy due to this rear brake issue.

 

[Bounce]

https://www.fjrforum.com/forum//index.php/topic/150102-avoiding-doubletriple-postings/

 

[HotRodZilla]

You do know that the rear caliper has its own reservoir under the right side panel, just above the foot peg? I'm thinking you're trying to bleed the rear brake and maybe your reservoir is empty.

I also think your brake pedal is sticky from lack of maintenance and needs to be pulled apart, cleaned and greased. These would be the most common solutions to the problems you're having. If that's not it, obviously, you have something else going on, that is VERY rare.

Let us know...

 

[snyderej]

Rear reservoir is full, front is also full, rear caliper is off the bike and not connected to the rear brake line. Rear master cylinder does move and seems to reach max pressure wen pressed. With the caliper off and the brake line dangling, no matter how hard I press the rear master cylinder no brake fluid comes out of the rear brake line. The rear master cylinder almost seems to be activating the front caliper but nothing goes to the rear. This worked fine all day on a 2 hour ride but initially stuck on the hard braking and then after cooling off wouldn't move again after that. The front feeling spongy is probably unrelated, just frustration. I'm thinking the post above dealing with the device that deals with the linked brakes has to be causing the blockage. I'll post again when I figure it out.

 

[RaYzerman19]

I'd cycle the ABS next step, see if that does it. I'd leave rear caliper disconnected just so fluid might flow and purge the ABS unit.

 

[Donal]

ABS test procedure courtesy of Ionbeam here ...............

Running the test, cycles the ABS pump and operates all of the shuttle valves. If you are lucky you may just dislodge whatever is causing the blockage.

I seem to remember reading another post somewhere where someone used compressed air to blow through the ports in the ABS block to remove debris. If you are at the point of replacing the block what have you got to lose?

 

[BentAero]

I had a Honda ST1300 10 years ago that had the exact same symptoms; rear brake started to drag intermittently, then with no warning it just 'stuck on' -while on the freeway, cherry-red glowing rotor included.

The master cyl seal had a micro leak, which let fluid get on the back-side of the seal (after a brake overpressure panic stop), which meant the piston couldn't retract. Since it couldn't retract, it was blocking the return bleed hole. Sort of a catch-22. All it needed was a master cylinder rebuild kit and all was healed.

 

[Harald]

I may have missed it, but did you try bleeding the right front caliper pistons that are connected to the rear brake master cylinder? The front, right, rear set of pistons are operated by the rear brake pedal. This would tell you if the master cylinder is working at all.

 

[gapiob]

when you try to brake with you're rear break, have you check if the right front brakes work?

With the coupling breack system, 2 of the 8-piston front works when you press rear break.

Mais je pense que vous l'auriez vous tout de suite si l'avant freinait tout le temps.
Du coup je penche plutot pour l'étrier arriere qui est grippé. j'ai eu se probleme sur un vieux k13RS, à chaque remplacement de plaquette, l'étrier n'était jamais nétoyer, ni graissé. du coup petit a petit, les poussieres de freins se sont mélangées a la crasse de la route, et on finit par suffisament bloquer l'étrier pour qu'il ne revienne pas en position apres un freinage. les plaquette sont resté en appuis faible sur le disque, et ont finit par s'enflamer... le copain a eu la peur de sa vie sur autoroute...
Je pense que malheureusement le diagnostique ABS ne donnera aucun résultat. l'ECU ABS test uniquement les valves/mecanisme de l'ABS, et là je pense que le probléme se situe hors ABS. au niveaux de l'étrier de freins

 

[gapiob]

All in English (sorry) with some errors corrected (Thanks for remarks)

when you try to stop with your rear brake, have you check if the right front brakes work?

With the coupling brake system, 2 of the 8-piston front works when you press rear break.

But I think you would note immediately if the front was holding all the time.
So I lean rather to the caliper back is seized. I had problem is an old k13RS, each replacement board, the bracket was never cleaned neither greased. So a small, brake dust have mixed a dirt road, and we end up sufficiently block the bracket so that it does not come back in position after braking. The wafer are kept in small presses on the disc, and eventually inflame ... the friend was the fear of his life on highway ...
I think unfortunately the ABS diagnostic will not work. ABS ECU test only valves / ABS mechanism, and there, I think the problem is outside ABS. At the level of the brake caliper.

 

[gapiob]

any news?

 

[snyderej]

I reinstalled the rear caliper. Bled the front linked caliper etc., no help. The rear does not get any fluid so I assume the ABS system that proportions the 2 is only letting fluid to the front. I will order the ABS master cylinder which I'm sure is the wrong definition but either way it's the block of metal on the right side of the bike all the brake lines feed into.

 

[Donal]

I reinstalled the rear caliper. Bled the front linked caliper etc., no help. The rear does not get any fluid so I assume the ABS system that proportions the 2 is only letting fluid to the front. I will order the ABS master cylinder which I'm sure is the wrong definition but either way it's the block of metal on the right side of the bike all the brake lines feed into.

That is a pretty expensive step to take without a bit more investigation.

From what you said: you can't get fluid to or from the rear caliper, you can get fluid to and from the front lower right set of pistons.

If that is correct there is almost certainly nothing wrong with your ABS block (the expensive part).

If you are getting fluid to & from the front caliper it sounds like your 'metering' valve is working.

If you are not getting fluid to & from your rear caliper your 'proportioning' valve is suspect.

You will need to identify the suspect valve block and then 'crack' the banjo bolts to check if you are getting fluid up to the suspect proportioning valve.

 

[RaYzerman19]

I would still try to loosen banjos at various points to see where the blockage point is. IIRC, there was a gent with a metering valve or proportioning valve issue. Worth doing before ordering an expensive ABS unit. There are used ones on ebay occasionally for around $200. You will loosen up most of these banjos to replace the ABS anyway...........

 

[snyderej]

I wanted to finish this thread with the issue and resolution. Yamaha ABS module can be bled using techniques described in other threads and trying to do this with the original ABS module which consists of 3 solenoids mounted to the module worked on one of the three (Front) but made no noise on the others. After checking ohms on the solenoids which appeared to be close but the 2 that would not function were different. I ordered a used unit on ebay and it came in with one bad solenoid (just my luck) so ordered another and that cured it. The solenoid either fails or gets something stuck in it and acts as a check valve when it fails. It will allow fluid to pass but not relieve back to the master which keeps pressure in the line to the caliper. Nothing you can do once it's really locked up except loosen the bleeder relieving the pressure and don't touch that brake until you get home.

 

[Mihalis fjr]

Repairable here with life time warranty
https://diag-engine.com/abs-pump-motorcycle/yamaha/2467-fjr-1300.htmlIf you buy a used one from ebay probably will have the same problem right now or in the short future..