When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Recently I had exactly the same issue, except mine are disc brakes.
I rebuild calipers, master cylinder, rubber lines, and cleared metal lines.
My master cylinder acted exactly as you described. I did all the things you did with the m/c.
After at least 10 unsuccessful attempts at bleeding, I threw up my hands in surrender and ordered a NEW m/c. First bleed after install and the system worked perfectly!
Yeah Im sick of messing with it, so I just ordered a drag specialties M/C. Its not worth the hassle (or the safety concern) at this point, especially given this will be my only brake.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.