Okay so it's a pleasant retro ride and has a few advantages over a completely stock FLH .
The front brake is complete crap . Complete and unadulterated crap . Even when it does work it's after 20 pulls straight to the grip and then and only then does it work . Release and commit to the same drill for each and every stop thereafter .

Look I've been in these things before and all it was , was parts replacement . this time something is different . Keep in mind I have 30 years of rice wrenching behind me as well as a smattering of H-D . I always questioned round O-ring in the caliper and have repeatedly asked about the sometimes called "friction ring/washer" in the groove at the bottom of the caliper . I have never had issues before but I suppose the one I own rather than a customer bike is ok .

Does this at all sound familiar to anyone ? It would be nice to have a real , operating , stopping , front brake ...

~kop

 

I had a brand new FX with similar brakes. From new they were as effective as you describe! However if the lever comes straight to the grip there is something wrong.

Your bike will reward skill and advance planning, while riding it. You will have difficulty improving things without doing major surgery.

Easy fixes are to replace the brake line with braided ones if you don't already have one. Also use after-market pads, such as Lyndall, if they make them for your bike.

After that you could consider transplanting a much later front end with larger rotor(s) and modern caliper.

 

As GRBrown hinted at, the old brake hose could be 'ballooning' under pressure and need to be replaced. Also, check the master - it may be leaking back during pull and not moving fluid efficiently. Not hard to rebuild.

 

Rebuild the master cylinder, it is not returning to full travel, a quite common problem, even with newer bikes. I honestly don't know how Harley ever got away with their braking systems, that even when brand new, worked about as well as dragging a rope.
I'd rebuild everything, including the by now rotten brake lines. Lyndall pads if avialble, if not, try SBS. Make sure the rotor is flat and true. FWIW Fastrider124

 

Okay here's the story . The pos just wouldn't work at all , bled , re O-ring'd ,cleaned , bearings and rotor checked for run-out ad nausea ...

So there is this old skool wrench in the area that tells me to put all the clearance on the back of the piston by backing off the four caliper bolts about a turn and a half then pumping up the brake with a tooth pick stuffed in the pressure relief hole in the master cylinder . Then he says to tighten the the four caliper bolts with the lever still pulled to the grip . Then slowly release the pressure from the relief hole ...
I now have a brake fluid stain on the ceiling of the garage and a completely bled and working front brake . He called about 10 minutes after the DOT 3 geyser to warn me about the extent of the pressure under the toothpick . I really should have known anyway but about four tries and as many beers into it I get to tell on myself . So in short bleed the brakes then separate the caliper halves by a turn or three then have a third hand apply the brake while the caliper halves are tightened down .
I celebrated b taking the bike over HWY 410 for dinner and actually had to use my new found brake to avoid a deer on the way home . All is well after a fashion and the brake works as well as can be expected for a 70's disc .

~kop