Have a similar fault with the ABS on my 2004 bike. There was a guy on ebay offering a rebuild, but when I enquired, he didn't rebuild the iABS units. I have also been in contact with rhelectronics in Germany about a rebuild. I have what they class as an AM1 unit. Stripped the unit off the bike today and had a little scout around. It appears to me that one of the pressure relief valves is a bit sticky. Any ideas where I can get one of these cheap before I send unit off for an expensive rebuild?