Just picked up a used 2004 RK Custom with 6k miles. I noticed the front brakes are less than desirable. The lever pulls almost all the way to the grip and still does not seem to brake very well. I have heard from others that the earlier models were like this. I know I am used to the newer brakes and ABS. But I would still like to see if there is a way to make these front brakes a little more grippy. That is without doing a full caliper change. That is just not in the budget at this point. The rear single brake has more grip than the dual fronts.

 

First thing - bleed them. There has got to be air in the lines if the lever pulls all the way back.

 

Worn pads can do this also. Especially if they've worn into a wedge and have to twist when engaged.

 

They may need bleeding but most likely don't.
What they most likely need is cleaning. Brake dust builds up around the pucks in the caliper causing them to hang up. If you clean the pucks your full lever will return.
Start by removing the front wheel which involves also removing the calipers.
When the calipers are off (do one side at a time) you can then remove the brake pads and then squeeze the lever until the pucks are nearly fully exposed. I don't think it's possible to pop the pucks clear out with the lever but be aware that it 'could' happen and pay attention.
Then spray the pucks with Brakleen (or the equivalent) and clean off all of the black brake dust from around the outside of the pucks. An old tooth brush works well here.
When you have them all cleaned off you can then use a large screw driver to spread the pucks back apart, reinstall the pads and put it all back together.
Note: I use a 1/2" socket placed inside the pucks to push them all the way into the caliper - you'll see what I mean when you get there.
Also, you don't necessarily have to completely remove the front wheel to accomplish the cleaning. I just pull the axle out so the wheel can be moved far enough to allow the calipers to be removed (yes I have a lift table).

 

Bleed 'em and flush out the old fluid. After bleeding, I will pump the lever a bunch of times then keeping pressure in the lever, zip tie the lever to the grip over night. That usually helps too.

 

Most likely the sponginess is from the old rubber brake lines. I changed the front brake lines on my 2002 RK with a steel braided set and it transformed the brake feel.

 

That would not be it. The previous owner had good quality steel braided lines installed with the apes.

 

I would start with the bleed and go from there, if needed.
Glad to hear you are back with us on two wheels again.
Ride safe, and enjoy the 'King!

 

I just was told recently that 02-04 vintage had F'd up machined calipers where an air pocket hangs and near impossible to remove, Anyway I just worked on my buddies 02 that had the same issue, I tore everything down and those years came with DOT 5 (purple fluid)there was DOT 3 or 4 in there because it was a blackened yellow. The orings in the calipers were rotted to the caliper bores, these were the hardest I have ever worked to rebuild brakes, they were toast. I rebuilt the m/c and calipers and went back with DOT 5 and it works killer, almost as good as my 07's.
Since your bike is 9 yars old I would only consider rebuilding the entire system.

 

You also may may need a rebuild kit for the master cylinder. Inexpensive item.