Rear ABS not working on my Gen 1

[Donal]

Have you tried testing your ABS as per this procedure?

 

[RadioHowie]

Back in the day, when my ABS DID work, I'd do some "experimenting"...

Driving through town, with MANY traffic lights, stop signs, bad drivers and stupid pedestrians, I'd use ONLY my rear brake.

I'd really hammer down on it, regardless of traffic or speed. Many times, the ABS would activate, but I'd stop FAST, straight and true.

Repeat over and over, probably to the point of nearly overheating my rear disc, but never ever failed to stop safely.

Unfortunately, that scenario just doesn't work now with MIA ABS, but, I CAN say that a car tire stops much straighter locked up than a motorcycle tire does.

 

[OldButNotDead (sockpuppet)]

HRZ, I really hit the front, probably harder than the rear. I thought as you say, hitting the front would cause the back to slice easier. Even tried going both up and down a slight grade, no change. May just say screw it. The brakes are stopping fine. No Donal I didn't because I haven't purchased the test clip.

Howie, I'm going to try it again when I can carry some more speed. What I can say that in my 35mph tests it stopped dead true, no bends, wobbles, slides or any other shenanigans. AND it brought the speed down QUICK.

 

[Donal]

Have a look here for a DIY test connector..........

 

[garyahouse]

Okedokee:

I removed my right side black inner cowling panel to expose my ABS connector. On my Gen 1, it's right next to the tank. After hooking up a couple alligator clips to jump the blue and black wires as instructed here CLICKY, I followed the instructions by turning on the key to verify what the ABS warning light would do. It came on for two seconds, then began blinking on and off continuously. Then, again following the directions, I...

• turned off kill switch
• turned on key, wait two seconds
• hit starter button for >4 seconds (don't worry: engine doesn't turn over)
• depress both front and rear brake levers and wait for front brake to pulse a couple times, then rear brake, then front, then rear...

The front brake pulsed, the rear did not. I could hear the little pump whirring away, I could hear and feel the pulsing in the front lever, but not the rear.

No error codes were displayed, unless there's something special or extra I need to do to get them to do so??? FSM says that if no codes are displayed, then the ABS ECU didn't record any.

What next?

Gary

darksider #44

 

[RadioHowie]

"What next?"

Two options:

1 - Cry a little and start hunting for a used ABS block on eBay, or

2 - Ignore it and remain aware that the ABS on the rear wheel is MIA.

 

[garyahouse]

May have found one at LKQ, but not SURE that this is indeed what I need. That's kind of the big question here.

I've already done the crying, and I'm already living with the MIA issue. But I'm wondering, before I dump a bunch of cash here, if there's anything else I should be checking. I know you've been down this road before, so thanks for the input.

Gary

 

[RadioHowie]

Nothing I can think of, my friend. You've done the tests and it failed. That's pretty much a wrap.

 

[rushes]

I wonder if anyone has tried forcing fluid backwards in the system to possibly dislodge a blockage?

Also, has anyone dissected one to try and determine what's causing these failures?

 

[HotRodZilla]

Drop it in a sonic cleaner for 12 hours. Donno if it will work, but it's very worth a try and pretty cheap.

 

[ionbeam]

Excerpted from a PM I sent to Gary:

Looks like you have done everything correctly and ended up with bad news. The failure to feel the rear brake pedal pulse is due to the valves in the metering block being stuck. So far nobody has found a fix. The ABS computer only knows that it commanded the spool to open but there is no feedback to let the ABS ECU know if the spool actually moved or not so there is no error code. If the spool solenoid failed to energize the ABS ECU would have set a code.
I have done a partial autopsy on a dead metering block and let me tell ya, there will be no fixing one of these by taking it apart. Many of the internal items are swaged in and have to be destructively drilled out. I have tried hitting the ports with compressed air @ 160 psi and it was unmoved. The owner of the metering block had beat the tar out of the metering block with a hammer as he commanded the valves to actuate but it didn't free anything up.

So far, the only thing that I can see that might fix a stuck spool valve would be Hotties suggestion of an ultrasonic cleaner and a stout solvent. I'd give it a slightly better than a 0% chance of working

 

[TomInPA]

Excerpted from a PM I sent to Gary:

Looks like you have done everything correctly and ended up with bad news. The failure to feel the rear brake pedal pulse is due to the valves in the metering block being stuck. So far nobody has found a fix. The ABS computer only knows that it commanded the spool to open but there is no feedback to let the ABS ECU know if the spool actually moved or not so there is no error code. If the spool solenoid failed to energize the ABS ECU would have set a code.
I have done a partial autopsy on a dead metering block and let me tell ya, there will be no fixing one of these by taking it apart. Many of the internal items are swaged in and have to be destructively drilled out. I have tried hitting the ports with compressed air @ 160 psi and it was unmoved. The owner of the metering block had beat the tar out of the metering block with a hammer as he commanded the valves to actuate but it didn't free anything up.

So far, the only thing that I can see that might fix a stuck spool valve would be Hotties suggestion of an ultrasonic cleaner and a stout solvent. I'd give it a slightly better than a 0% chance of working

So far, no one has reported on the root cause of the failure. If the spools are indeed frozen, is it corrosion from aluminum, or a failure of the motive power source? Is there any obvious fusion of the spools to the cylinder walls?

The most constructive comment I have heard, is for owners of vehicles with failed ABS systems to make a precise report of the failure of the rear ABS to NHTSA. If this failure is common, and safety related, it should eventually become a recall or at least a service bulletin issue.

 

[TomInPA]

Bugs! I hate bugs!

 

[mcatrophy]

... it should eventually become a recall or at least a service bulletin issue.

First question will be, "Has the fluid been changed evey two years as per Yamaha's service interval?"
After all, if your brake pads wear out and your brakes don't work, no-one would expect that to be the subject of a recall, because you haven't followed the service recommendations. Moisture absorbed into the fluid is likely to cause corrosion, so it's a reasonable requirement.

 

[garyahouse]

Copied from a recent PM from Ionbeam:

Hi Gary,

Looks like you have done everything correctly and ended up with bad news. The failure to feel the rear brake pedal pulse is due to the valves in the metering block being stuck. So far nobody has found a fix. The ABS computer only knows that it commanded the spool to open but there is no feedback to let the ABS ECU know if the spool actually moved or not so there is no error code.

I have done a partial autopsy on a dead metering block and let me tell ya, there will be no fixing one of these by taking it apart. Many of the internal items are swaged in and have to be destructively drilled out. I have tried hitting the ports with compressed air @ 160 psi and it was unmoved. The owner of the metering block had beat the tar out of the metering block with a hammer as he commanded the valves to actuate but it didn't free anything up.

Sorry for the bad news

but at least you have confirmation of what the problem actually is.

Alan

 

[garyahouse]

One last question before I attempt to order another and then eventually pull my metering block. When checking with a volt meter as recommended in the FSM, as soon as I turn on the key, the system starts throwing a code that's not really a code. I've figured out that the timing between the pulses on the meter determines the code, sort of like the old morse code system. One long interval between pulses = a digit in the 10's column, and a short interval between pulses equals a digit in the 1's column. Those of you in the know about reading the codes already know this. Anyway, I'm learning.

 

[garyahouse]

One last question before I attempt to order another and then eventually pull my metering block. When checking with a volt meter as recommended in the FSM, as soon as I turn on the key, the system starts throwing a code that's not really a code. I've figured out that the timing between the pulses on the meter determines the code, sort of like the old morse code system. One long interval between pulses = a digit in the 10's column, and a short interval between pulses equals a digit in the 1's column. Those of you in the know about reading the codes already know this. Anyway, I'm learning.

 

[garyahouse]

One last question before I attempt to order another and then eventually pull my metering block. When checking with a volt meter as recommended in the FSM, as soon as I turn on the key, the system starts throwing a code that's not really a code. I've figured out that the timing between the pulses on the meter determines the code, sort of like the old morse code system. One long interval between pulses = a digit in the 10's column, and a short interval between pulses equals a digit in the 1's column. Those of you in the know about reading the codes already know this. Anyway, I'm learning.

 

[garyahouse]

Omit this duplicate post

 

[garyahouse]

Help...

One last question before I actually attempt to find another metering block and then eventually pull my own metering block off the bike. As you can guess, this decision will cost me a good chunk of change... if I can even FIND another metering block. So bear with me here.

When checking with a volt meter as recommended in the FSM, as soon as I turn on the key, the system starts throwing a code that I'm thinking is not really a code. I've figured out that the length of the pulse and the timing between the pulses on the meter determines the code, sort of like the old morse code system. One long pulse = a digit in the 10's column, and a short pulse = a digit in the 1's column. Those of you in the know about reading the codes already know this. Anyway, I'm learning.

However, my FJR only throws one code: which doesn't seem to be a code at all. It gives one second pulses with one second intervals between pulses constantly with no change or pause in the timing or duration. I'm assuming this is normal and indicates that there is no code to be found.

???

Gary

darksider #44