Motorcycle Repair: ABS braking problem, piston cups, brake master cylinder

Question
Goldwing 1800. Year,  2006.  Press on brake pedal and it goes down 2 plus inches.  pump 1 or 2 times and comes up and stay up.  when I let up and then press down again, again 1 to 2 inches.  Brakes are ABS

Answer
John, I am not a GW expert, especially on ABS problems. There are lots of GW sites that probably have specific answers for you, though.

http://www.goldwingworld.com/Brakes-wheels-tiresgl1800.pdf

A warped rotor would make the brakes act like that, but you would feel the pulsing in the pedal during brake operation.

In general, the symptom you describe sounds like air in the system. I don't know if the ABS pump is self bleeding when they cycle or not, but I would try bleeding the brakes first. If there is no air present, then the next best guess would be that the rear brake master cylinder piston cups are worn/gummed up, which prevents a good pressure surge when the brakes are applied.

Bill Silver