Rear Brake issues

[eng943]

While riding with my wife today, I noticed the rear brake was almost absent. Switching from linked to less linked modes did nothing.

I tried using only the rear brake, and on initial application I got no braking at all. Pumping the rear brake, I did get some braking.

Any ideas? I just installed the AST lowering brakets.   

[JerBear]

There has been a lot of issues with the rear brakes abs pump not working properly due to lack of Maintenance changing fluids regularly is the most likely culprit..  Most of the problems were on first gen bikes (08-09) but there may have been later years as well.  Does the ABS engage properly?  just search for rear abs and you will probably find a lot of info. 
http://forum.cog-online.org/concours-14-zg1400-general-chat-and-tech/bad-abs-pump/

[just gone]

I tried using only the rear brake, and on initial application I got no braking at all. Pumping the rear brake, I did get some braking.

JerBear could be correct, but whenever that's happened to me (auto or motorcycle) it was always low brake fluid or air in the system.
 I think I'd bleed the back brake before I looked into the ABS.

[lather]

Another idea. If initial brake application gives nothing but pumping gives result it could be a warped rotor. The warp pushes the piston in while running so the first application of brake just takes up the slack. Takes more pressure to clamp the rotor.

[jimmymac]

Another idea. If initial brake application gives nothing but pumping gives result it could be a warped rotor. The warp pushes the piston in while running so the first application of brake just takes up the slack. Takes more pressure to clamp the rotor.

This is where my mind went as well.

[VirginiaJim]

Warp on the rear?  The rear caliper doesn't have the ooomph to warp a rotor, much less stop the bike (Yes, it's probably happened on someone's bike but it's so remote).  I'm thinking air in the line that could be from the rear master or the caliper itself.

This is where my mind went as well.

Glad you  know where yours went.  I still can't find mine.

While riding with my wife today, I noticed the rear brake was almost absent. Switching from linked to less linked modes did nothing.

I tried using only the rear brake, and on initial application I got no braking at all. Pumping the rear brake, I did get some braking.

Any ideas? I just installed the AST lowering brakets.   

Have you tried riding without the wife?  I'm still thinking air in the line.  Did you notice this before or after the AST installation?

[eng943]

I did not notice is before the AST install. I wonder if the line stretched enough to allow some air in the line. I'll try bleeding it and see what that does.