Alternate front brake master cylinder?

[Elipten]

I am far advanced in a significant rebuild of my 1990 K75RT.

I cannot get the front brake to be very hard after numerous efforts to bleed (I am sure there is no air).  No matter what the lever goes very far back and if I squeeze I can get the lever to bottom out on the grip.

So I am assuming the master cylinder is leaking. 

Are there any higher volume or better alternatives than the original BMW part?  If I'm going to spend close to $300 for a OEM BMW part I might as well look at options and maybe upgrade performance.  Also putting in a stainless steel line while I'm at it.

[mystic red]

Master Cylinder Rebuild

[wmax351]

The stainless lines will help a lot. The ratios on the K bike brakes are pretty high, especially compared to sport bikes, so the lever will have some squish. Any aftermarket master cylinder would require the replacement of the entire right side handgrip, throttle, switches, etc. Not worth it.