ABS issue - pulses then skids

[betoney]

I recently replaced my brake lines with braided lines, ABS pump was not unplugged or removed from the bike.  One line replaced at a time.  The brakes work fine but today I decided to try the ABS function on damp pavement.  I pressed firmly on the rear pedal and it pulsed 2-3 times like normal and then locked up into a skid.  I decided to check the front so I rode through some loose gravel slowly and grabbed the brake lever, again, pulses 2-3 times and skids to a stop.  I checked it many times and could not get ABS to gradually slow the bike, the ABS light comes on and I have to cycle the key on/off to clear the warning light but the ABS light only comes on during the skid, not under normal riding.

Both pedal and lever feel firm (proper bleed, not spongy) and the brakes work normally until the ABS module activates, there are no error codes on the screen. 

Any thoughts or experience with ABS issues?

Edited December 27, 2019 by betoney

[koth442]

Interesting. I've not heard of this issue before. I'm curious what others have to say.

[roadrash83]

 For what it's worth I just finished the lines on my 19 GT,  the lever- petal feel great but the ABS is not acting right but no ABS light. From what I have been able to determine the dealer needs to cycle the ABS pump with his dealer only tool to flush the system and reset the system. This is not coming from the dealer but from what I have read on the world wide web "so it must be true". I'm taking my bike by the dealer tomorrow to so what they have to say, I'll let you now tomorrow👍

[betoney]

4 minutes ago, roadrash83 said:

 For what it's worth I just finished the lines on my 19 GT,  the lever- petal feel great but the ABS is not acting right but no ABS light. From what I have been able to determine the dealer needs to cycle the ABS pump with his dealer only tool to flush the system and reset the system. This is not coming from the dealer but from what I have read on the world wide web "so it must be true". I'm taking my bike by the dealer tomorrow to so what they have to say, I'll let you now tomorrow👍

Thanks for the info.  I was thinking along those same lines.  I'll be interested to hear what your mechanic finds. 👍😎

[texscottyd]

Following with great interest.   I’ll be installing my new Galfer lines in the next couple of weeks, so anxious to hear if there is an additional step in the process   

[betoney]

59 minutes ago, texscottyd said:

Following with great interest.   I’ll be installing my new Galfer lines in the next couple of weeks, so anxious to hear if there is an additional step in the process   

Yeah, I'm hoping its something simple because it sure doesn't make any sense to me.  The only thing that changed on the ABS pump itself was removing and replacing 4 banjo bolts, the pump remained full of brake fluid.  I might have to see if I can make it to the dealer to get it checked tomorrow or Saturday like @roadrash83 suggested.

[BBB]

I’ve had this type of problem with older cars, so it may have some relevance here. Now that you’ve cycled the ABS pump, try bleeding each line again. You may have freed bubbles that had accumulated in the ABS pump.

[betoney]

35 minutes ago, BBB said:

Now that you’ve cycled the ABS pump, try bleeding each line again. You may have freed bubbles that had accumulated in the ABS pump.

I will give that a try, thanks.  👍

[chitown]

 

14 hours ago, roadrash83 said:

 For what it's worth I just finished the lines on my 19 GT,  the lever- petal feel great but the ABS is not acting right but no ABS light. From what I have been able to determine the dealer needs to cycle the ABS pump with his dealer only tool to flush the system and reset the system. This is not coming from the dealer but from what I have read on the world wide web "so it must be true". I'm taking my bike by the dealer tomorrow to so what they have to say, I'll let you now tomorrow👍

Don't know about the GT but the shop manual for an FJ-09 doesn't call for any such procedure to flush or reset anything. Have heard other motorcycles with ABS have such a thing but none of my Yamahas with ABS call for it in the shop manuals ('15 FJ09, '05 FJR 1300). 

The only item different for the FJ-09 from bleeding any old system is that the manual specifies an order, bleeding front first then rear. 

There is a "hydraulic unit operation test" that requires a diagnostic tool that is to be performed AFTER bleeding. Have bled my system a few times, including at brake line replacement, and never did the test nor experienced any problems. Of course, now that someone has had problems that test might prove useful. 

 

Edited December 27, 2019 by chitown
typo

[skipperT]

Great suggestion @BBB. Now that the inner workings of the abs unit have been activated, some air may have been pushed into the lines where it can easily be bled out the main 3 calipers. 

the service manual details a way to pull codes @betoney - but I wouldn’t worry about that yet unless you’re curious. They can be read and cleared similar to being in DIAG mode once the abs coupler has been jumped IIRC. 
Full bleed and another test ride should fix it. 
Keep us posted,

-Skip
 

[coachluciano]

1 hour ago, betoney said:

I will give that a try, thanks.  👍

I was kinda thinking that too, but didn’t have any knowledge to base it on

[roadrash83]

@betoney and @texscottyd I took the bike up to the dealer this morning and had them flush and activate the ABS pump with their scan tool. the brake petal and lever feel great, the ABS works as it should. They said you need the tool to properly bleed and flush out the ABS. The Tracer is not like the older Yamaha that you can jump the wires to activate the pump. Total cost was $112.00😢

[betoney]

3 minutes ago, roadrash83 said:

@betoney and @texscottyd I took the bike up to the dealer this morning and had them flush and activate the ABS pump with their scan tool. the brake petal and lever feel great, the ABS works as it should. They said you need the tool to properly bleed and flush out the ABS. The Tracer is not like the older Yamaha that you can jump the wires to activate the pump. Total cost was $112.00😢

Thanks for the info, glad to hear that it is working properly now.  Did they give any indication as to why this happened?  Surely it shouldn't be "required" as part of replacing the brake lines?

I guess I will get the bike to the dealer in the near future. 

[texscottyd]

Very interesting... much appreciated information, @roadrash83.   With mine being a 2015 FJ, I wonder if the process is the same?   I’m have a factory service manual, so will dig into it and see what I find.    The brakes on mine feel kind of wooden right now (even with the big rotors and HH pads), so I’m anxious to get the lines installed & fresh fluid through the system.   

[roadrash83]

1 hour ago, betoney said:

Thanks for the info, glad to hear that it is working properly now.  Did they give any indication as to why this happened?  Surely it shouldn't be "required" as part of replacing the brake lines?

I guess I will get the bike to the dealer in the near future. 

@betoney When the brake system was opened up to replace the lines air gets into the system, specifically the ABS unit so the unit must be bleed. When you are just flushing as part of routine maintenance you flush the brakes then get ABS to activate, then flush the system again to remove the old fluid that came out of the ABS pump by flushing the system again ( no air entered the system).  The tech at the dealer ship said be glad you don't have an MV they call for purging the system 5 time for a fluid flush.