How I removed servo iabs brakes on my 05 :clap

Discussion in 'GS Boxers' started by drdata, Jul 13, 2014.

  1. drdata

    drdata R1200GS

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    Hey all, see below for context:
    http://www.advrider.com/forums/showthread.php?t=975707
    http://advrider.com/forums/showthread.php?p=24555835

    The purpose of this thread is to document the removal of servo iabs from my 05 gs to convert to regular brakes.

    First, the legal stuff.

    You should not attempt this. I am no expert. ABS brakes can save your life. You will loose abs and brake linking as well as power assist. You will have to attend Harley training so as to be able to "lay 'er down" in the event you need to stop at over .25 Gs. ;)

    If you do this, you will mostly likely die. This is for information only.

    Now for the how to. I plan to break (pun intended) this down into three parts:

    1. Rear brake
    2. Font brake
    3. servo-ectmy and whatever fallout ensues, such as broken speedo.


    Edit: now complete except for final speedo test. So far the brakes feel fine and blinkers/brake light is working.
    #1
  2. drdata

    drdata R1200GS

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    In this part I detail re-plumbing the rear brake line direct to the master cylinder to bypass the servo unit.

    I believe the right way is to get part number ! and 4 as shown in:

    http://www.advrider.com/forums/showpost.php?p=24554537&postcount=17

    I chose to do this with minimal cost, and so simply rerouted the brake line to the MC. The downside is choosing the ideal routing was the hardest part of the job, and in the end I would be worried that jumping/maximum suspension travel may stress the line leading to failure and loss of rear break.

    That said, in my current servo fail mode rear brake is gone. Could not lock in residual. After direct MC connection and bleed, the rear wheel locks quite easily, with ignition off!

    1. Tools and materials.

    Screwdriver to remove clip on brake line, t30 and t40, dot 4 fluid for flush, some clear hose, and channel locks to hold the MC while removing/attaching dome nut. The metal fitting is not needed if going direct to MC, but the part should be retained. It is used if you buy the hardline suggested above.

    The 8MM wrench is for bleed nipple, the 11 mm is for the hardline nut that attaches to the rear MC.

    Attached Files:

    #2
  3. drdata

    drdata R1200GS

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    Part 1:b

    Here is a pic of the oem setup. OP from the MC is routed up to the servo module, where magic either does r does not happen, the servo ouput is then routed back down the hardline on the right, where it attaches through a fitting to the rear brake line:

    Attached Files:

    #3
  4. drdata

    drdata R1200GS

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    Here is a pic showing the left side view of the oem fitting that runs the servo output to the rear wheel cylinder.

    Attached Files:

    #4
  5. drdata

    drdata R1200GS

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    Here you can see the clip pulled out of the fitting and the fluid draining from the hard line that feeds the servo OP back to the wheel. You can also see the hardline with 11mm nut that feed the MC output up to the servo. You will remove the nut and attach the brake line dome nut directly to the MC:

    Attached Files:

    #5
  6. drdata

    drdata R1200GS

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    To access the t40 that secures the dome nut to the fitting I found it best to remove the fitting itself (held with a single torx), which gives access to the dome nut:

    Attached Files:

    #6
  7. drdata

    drdata R1200GS

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    And now the hard part of this easy job. Deciding how best to route the brake line. eaither option has it's downside. Seems to be some stress on the line/fitting, and the potential for pinching/chafing on the chassis.

    I tried an "over the strut" approach, but opted against it as it seemed suspension travel would impinge the line:

    To be clear, this is, IMO, how NOT to run the line:

    Attached Files:

    #7
  8. drdata

    drdata R1200GS

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    Here is a pic showing the routing I settled on. The down side is the fitting has to stick out to the right a bit to avoid rubbing on the swing arm. Possible your boot can rub on it, etc.

    Attached Files:

    #8
  9. drdata

    drdata R1200GS

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    Another view of the brake line routing:

    Attached Files:

    #9
  10. drdata

    drdata R1200GS

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    Wanted to add that I was not able to access the the top pf the MC to screw on the dome nut due torx bit being too long. As such, I remove the rear MC for access. Simply remove the linkage clip at the bottom and then the two t30 torx to remove.

    Here you can see the two copper crush washers (or at least the bottom one). There is another between the dome screw and the fitting.

    Last step, bleed the rear brakes. No complexities, funnels, or other BS. Just bleed out and enjoy your new non-linked rear brake, which if you had a fault such as mine, is now working.

    Attached Files:

    #10
  11. aage

    aage Been here awhile

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    Thanks for detailed description of this conversion. I also have 2005 R1200gs and this info might get very useful in the future :-).
    #11
  12. drdata

    drdata R1200GS

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    This part was pretty simple. I opted to make no grinds to the frame tab, nor to cut the oem bracket.

    The down side is the bracket rids on top of the frame tab. If you over-torque the bolt you will bend the bracket.

    First, tools used. 8mm for bleed, 11 and 12mm for the hardline nuts, t30 and t40 for the bracket bolt and dome screws, and channel locks to hold bracket while dealing with dome heads. If not careful the bracket will bend. Dot 4 for bleed.

    Attached Files:

    #12
  13. drdata

    drdata R1200GS

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    Here is the oem setup. The MC comes in on the top right and feed through the hardline at top left to the servo. Again, magic does or does not happen there, and the fluid returns via the lower left and on out the lower right to affect the calipers.

    A t30 holds the bracket. Support with channel locks to avoid bending when removing the domes, and note the two different nut sizes on the hardlines.

    You will be using the two fittings on the lower half to make the MC to caliper connection.

    You don't have to remove the tank to do this, but as part three involves removing the servo and its hard lines I figured might as well take it off and make things easy. It's only 105.6 right now...

    Attached Files:

    #13
  14. drdata

    drdata R1200GS

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    And here is the final solution as it were. I opted not to cut the bracket or grind the frame tab, but believe the screw has enough purchase to keep things secure. If you over tighten with the tab in place the bracket will bend.

    Attached Files:

    #14
  15. drdata

    drdata R1200GS

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    Aside from a final bleed, I wanted to add that I needed to reroute the MC line to be outside the forks, else the line would stretch at full left turn. As a result it rubs/rides on the plastic. I may tie off to keep it from vibrating. Seems to be slack in both the wheel and mc circuits at full turn.

    Attached Files:

    #15
  16. drdata

    drdata R1200GS

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    This part went pretty fast. Hardest part was trying to snake the rear MC hard line out. Perhaps if I had removed the oddyesy battery. I ended up bending it straight on one end.

    Also, I bought a set of security torx at pep-boys that did not fit. They were 6-star and the fasteners on the abs pump are 5. I ended up using a 7/32 drill to remove the screw heads to split the brain. So much for no irreversible modifications.

    A quick test showed the blinkers and brake light working. Will get back with speedo result after I get the tank back on.

    A slight concern here is heat and the elements for the ABS brain. For now simply wrapped in a 1 gallon zip lock. In the OEM arrangement the electronics are sealed into the abs pump, so air circulation is not an issue, but the pump housing itself may act as a big heat sync.

    Tools used are snips for tie-wraps, t30 for abs pump mounting, screwdriver to remove the hard-line clips.

    Attached Files:

    #16
  17. drdata

    drdata R1200GS

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    Removing abs pump connections. The front left leaked a bit. Turkey baster to drain is an idea. Two electrical connectors removed. The left side front and rear hardlines out, middle ones left to go. Just pull up the rubber cap and remove the spring clip. I only lost one.

    Attached Files:

    #17
  18. drdata

    drdata R1200GS

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    With the two electrical connectors and the 4 hardlines removed, all that is left topside is to remove main connector; push in lock tab and lift up handle:

    Attached Files:

    #18
  19. drdata

    drdata R1200GS

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    And, drumbeat please, here we have the servo unit gone. One rear hardline remains. Removing air horn helps in getting the rear lines out. The one that ran to the rear MC ended up getting bent as I was too hot to remove the battery.

    And now time to actually remove the beast. There are 3 T30 bolts holding in the servo. Two accessible from the left, one from the right. All came free easy-peasy and the unit lifted right out, like it was made to.

    Attached Files:

    #19
  20. drdata

    drdata R1200GS

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    the servo unit is drilled out to split. The two ribbon cables are removed from the "brain" side, all others are removed from hydraulic side.

    Look at the gauge on the power plugs for the two servo units. My alternator and battery will thank me.

    edit to add: I drilled it because the security bits I had did not fit. I had no plans to have the unit rebuilt so the drill was fastest option. I believe they are called male security torx. The kind with the male post in the middle that keeps a standard bit from inserting.
    See:
    http://advrider.com/index.php?threads/2005-1200gs-abs-delete-help-needed.991572/#post-24554537


    [​IMG]

    Attached Files:

    #20
    lost but retired likes this.