Hi all, new around here. Been struggling with trying to figure out what’s going on with my 2004 roadster for months. Front brake pressure has a tendency to give out randomly and takes pumping the brake to get that pressure back again. Bled the brakes but it seems to have made no difference, I’m at a loss. I’ve searched through forums all across the internet but it seems no one has had this problem that wasn’t a clear solution. Roadster has the dual front calipers and about 15k miles

 

My first suspect would be the master cylinder. You could replace it(my choice) or rebuild it. Try bleeding it again first though might be air in the brake line.

 

Try bleeding it on the right way again, after bleeding you squeeze the brakelever untill it feel heavy. While holding it squeezed put a strap around the brakelever and handlebar and let it sit
that way overnight. Next day remove the strap and see wath the result is, in many cases it will be solved. If not follow the advice from vonh12.

 

Have the same issue with my '03 sport, but I am converting to XR brakes.

 

The trick with dual brakes is to bleed them at the same time, I have a splitter on my compressor powerd bleeder for bleeding duals, it works fine and then do the procedure as I told
it works in most cases.