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Discussion Starter #1 (Edited)
Just wondering if anyone knows if you could disable just the rear circuit of the ABS system? I found on gravel roads it would be great to have manual control of the rear brake. Happy to have abs working up front. If this is not feasible, what is the best approach to putting in an abs kill switch for the whole system?
 

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I tried to do it electronically and could only disable the entire system, both front and rear. Due to the ABS being connected to the ECU in line with the traction control disconnecting or both of the wheel speed sensors throwing an ECU (FI on the dash) fault. I suppose someone with some electronics nouse could work out a solution given time. I posted about that here

I found the rear brake to be effectively useless off pavement beacuse of the ABS settings and pretty much stopped using it, hardly satisfactory.
I decided to hydraulically bypass the ABS circuit for the rear brake, two plugs into the ABS pump and a braided line directly from master to slave cylinder. Works perfectly, no fault codes, front ABS works fine and I can do skids for days! Finally might impress a lady by showing off on my V-Strom!:grin2:
 

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I decided to hydraulically bypass the ABS circuit for the rear brake, two plugs into the ABS pump and a braided line directly from master to slave cylinder. Works perfectly, no fault codes, front ABS works fine and I can do skids for days! Finally might impress a lady by showing off on my V-Strom!:grin2:
I'm curious, how well have the plugs worked for closing off the rear ABS circuit (and preserving it)? Wouldn't the ABS pump pop one of those plugs out the first time it cycled? I wonder if one could rig up a closed loop brake line for the rear ABS circuit. Might be tricky getting all of the air out of the tube without a central valve or something. Maybe even an "H" style bypass valve arrangement that could be manually switched when needed. Keeping it bled may be challenging though.

From what I recall reading the service manual's description of the ABS system, there is a single pump that works both the front and rear. The ability to control which wheel feels the affects comes from independently controlled solenoids. Since it was presumably designed to handle the pump running with only one of the solenoids actuated, it shouldn't hurt it at all to disable one of the solenoids. Although disabling one solenoid and then actuating the pump with NO solenoid open might be a different story. Trouble is, how to access and add a switch in-line with an individual solenoid's power? I'd have to review the diagram again. If I recall correctly, the solenoids are internal to the ABS unit. If we are lucky, then each solenoid has a direct line from the ECU, which could easily be interrupted with a switch. However, if there is just the speed sensor inputs or a data line and the ABS unit decides how to act internally, we are likely out of luck.
 

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I'm curious, how well have the plugs worked for closing off the rear ABS circuit (and preserving it)? Wouldn't the ABS pump pop one of those plugs out the first time it cycled? I wonder if one could rig up a closed loop brake line for the rear ABS circuit. Might be tricky getting all of the air out of the tube without a central valve or something. Maybe even an "H" style bypass valve arrangement that could be manually switched when needed. Keeping it bled may be challenging though.

From what I recall reading the service manual's description of the ABS system, there is a single pump that works both the front and rear. The ability to control which wheel feels the affects comes from independently controlled solenoids. Since it was presumably designed to handle the pump running with only one of the solenoids actuated, it shouldn't hurt it at all to disable one of the solenoids. Although disabling one solenoid and then actuating the pump with NO solenoid open might be a different story. Trouble is, how to access and add a switch in-line with an individual solenoid's power? I'd have to review the diagram again. If I recall correctly, the solenoids are internal to the ABS unit. If we are lucky, then each solenoid has a direct line from the ECU, which could easily be interrupted with a switch. However, if there is just the speed sensor inputs or a data line and the ABS unit decides how to act internally, we are likely out of luck.
Well firstly, about the plugs, they're SAE ⅛ thread (I believe) brake plugs, if they blew out the standard brake line fittings would have a long time ago.
Now I'm obviously not as well versed as you on the internals of that ABS unit so my simpleton logic is all I have to go by.
There is no longer any pressure input from the master cylinder, so effectively no pressure on that side of the circuit at all (that also means those plugs are pretty secure) the ABS system doesn't see a need to intervene so just sits idle. I've been running this for a couple of months and about 3000km of mostly gravel and dirt with some more technical stuff thrown in for kicks, zero issues apart from wearing the rear pads out faster;)

Sent from my SM-G930F using Tapatalk
 

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Ah, well that makes more sense... For some reason I was envisioning the plastic plugs that come with a new unit. DOH! Metal threaded plugs should do the trick.

The ABS pump and rear solenoid should open and operate whenever the ECU senses a stoppage on the rear wheel speed sensor while the front wheel speed sensor is still going. You won't feel it in the pedal of course, since yours is no longer tied into that circuit and any noise the pump makes is likely too soft for you to hear as well.

It would be interesting to know if after dead-heading the rear ABS circuit against the plug for an extended period causes the ABS unit any problems. But even if you restored it to normal service many years from now, it would be difficult to isolate the actual cause if an issue is discovered. Was it from dead-heading? Or lack of being lubricated by brake fluid while running? Or lack of flushing out old residual brake fluid once it goes nasty? Etc...

Since there is only one pump and independently controlled ABS circuits, it stands to reason that each solenoid can either handle being pumped against when closed, or has an internal bypass when closed. If the former, then my only concern would be the extra work the pump has to endure against two closed solenoids (a situation that should never naturally exist in the as built setup). If the latter, then it shouldn't matter if the pump runs without any open solenoids. I think it would be worth another look at the diagram to see if the rear solenoid can be disabled by a switch or not. But even if we can disable the rear solenoid externally, someone would eventually have to try it at the risk of their ABS unit...
 

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Ah, well that makes more sense... For some reason I was envisioning the plastic plugs that come with a new unit. DOH! Metal threaded plugs should do the trick.

The ABS pump and rear solenoid should open and operate whenever the ECU senses a stoppage on the rear wheel speed sensor while the front wheel speed sensor is still going. You won't feel it in the pedal of course, since yours is no longer tied into that circuit and any noise the pump makes is likely too soft for you to hear as well.

It would be interesting to know if after dead-heading the rear ABS circuit against the plug for an extended period causes the ABS unit any problems. But even if you restored it to normal service many years from now, it would be difficult to isolate the actual cause if an issue is discovered. Was it from dead-heading? Or lack of being lubricated by brake fluid while running? Or lack of flushing out old residual brake fluid once it goes nasty? Etc...

Since there is only one pump and independently controlled ABS circuits, it stands to reason that each solenoid can either handle being pumped against when closed, or has an internal bypass when closed. If the former, then my only concern would be the extra work the pump has to endure against two closed solenoids (a situation that should never naturally exist in the as built setup). If the latter, then it shouldn't matter if the pump runs without any open solenoids. I think it would be worth another look at the diagram to see if the rear solenoid can be disabled by a switch or not. But even if we can disable the rear solenoid externally, someone would eventually have to try it at the risk of their ABS unit...
I suppose I could plumb in a parallel brake circuit into the ABS and run it on the stand to see what happens, personally if the ABS unit dies I won't be overcome with grief but it would be nice to know whats going on down there, I said something along those lines to my proctologist the other day:wink2:
 

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Looks like (at least for the 2014 DL1000) that the solenoids are all controlled internally within the ABS unit. So it is unlikely that we will be able to disable just the rear.
 
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