There's no 'rear' ABS pump. There's only one pump in the system, even on cars. Pressure is regulated to the wheels via valves. If the system fails, brakes operate normally, just without the ABS function. Plus you'd get an ABS warning light as well, therefore ABS module failure doesn't seem to be your problem. However, it still could be the ABS module due to lack of maintenance (regular bleeding jobs), which wouldn't trigger a dash light if the electronics are working correctly. If you just bled the braking system for the first time, you'd not only have to possibly look at a new ABS module, but clean and rebuild all calipers and master cylinders as well. The braking symptoms you mentioned could be sticky caliper pistons. Whether properly serviced or not, your best bet is to let a dealer hook up the computer to test it. You need special equipment to clean an ABS module due to having to activate pump, all valves, etc. Or buy a new one. Plus I'd clean and/or rebuild all other braking components, including calipers and master cylinders. It's your life on the line. Good luck.
As a final thought, and whether it's your problem or not, hope this scares owners to spend the $5 needed for a small bottle to bleed their braking systems, as well as the half hour to do the job (or pay somebody if you're lazy ). It's a piece of cake. Absolutely no reason to neglect such a simple and cheap service, when brakes are the most important system in any vehicle. And the exhorbitant cost to fix such easily maintained components. Hope this helps.
As usual, your expert opinion, based on time with this bike, is full of holes. I have Owned one of the first C14's to hit the USA, and it has ABS. I have changed the brake fluids 3 times since purchase 7/07, and will do another this coming spring. The ABS module
is subject to failure, and a few documented cases on this issue have been aired here, and on the COG forum, over the years. A failure on the distribution valves in the module
WILL cause solid brake pedal lockup on the rear brake, and such has been documented (when the bike is running). Servicing the fluids requires no power to the bike or to the ABS system, which when the bike is "off" the circuits are in the passive mode. When the ABS unit fails, normal braking will NOT occur, and the failure is not always evident to the onboard diagnostics, so warnings on the dash
may not reveal it. The normal fluid changeout to prevent issues is not really all that simple, as when you do the job completely, it is easy to admit air into the system, but with due diligence the integrity can be restored.It is a bit more than "bleeding" the brakes, you need to completely flush the system, which means you will purge, and replace the fluids completely... i.e. running about a pint and a half, or more, thru to complete the action.
Same goes for the clutch...as it contaminates at an accelerated rate more so than the brakes.
I put together a deal with a Kaw dealer to cover our extended warranties at a great price reduction, specifically as a benefit to my family of COG, and have pressed it as a suggested purchase for 7 years now. replacing that pump unit is a pricey thing.
Coupled with regular service interval steps as outlined in the owners book that came with the bike, the checklist is pretty simple.