K1200GT rear brake problem - calling experts!

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OomD

Grey Hound
WD Supporter
Joined
Apr 11, 2013
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Location
Centurion
Bike
KTM 690 Adventure
I took apart the abs of my K1200GT 2006 and fixed the motor, abs module seems to operate properly now. But, I am unable to get any pressure into the rear brakes. This is not the servo-assisted brakes, but the iABS gen 2, if my google-fu is anything to go by.

I have bled the front after reinstalling the abs, all fine and well. The rear simply does not seem to push fluid to the calipers, the pedal does not get hard. So I pushed fluid from the rear up to the abs with a syringe, and from the abs up to the reservoir. Finally I pushed new fluid from the rear (bleed nipple) through to the reservoir, to make sure the abs unit wasn't doing something funny. The circuit is thus mostly full of fluid, yet the rear pedal builds no pressure.

Using the GS-911 I see the front goes up to about 12 bar with “normal” pressur e on the lever, and goes well over 30 bar if I squeeze tight. The rear goes up to 1.6bar when I push the pedal all the way down.

Any advice? Seems to me it might be the rear master cylinder, but before taking it apart I thought I'd ask opinions. I noticed small flaky white stuff in the brake fluid when I sucked out the rear reservoir with a syringe, dunno if this could've been part of a seal in the master cylinder?
 
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