i have an 05 road king with about 40.000+ miles. when the bike was new the front brake lever only moved a short ways to stop the bike. now if i haven"t used the brake for a while the lever will pull back until the dogleg nearly touches the throttle. if i am holding the throttle with two fingers and pulling the brake with the other two it pulls to the point of squeezing my fingers. i can pump the lever a time or two and the lever stops out where it is supposed to. the pads have been replaced once and have some wear but not enough to cause problems.(had this problem before replacing pads) fluid is up in the reservoir. i have tried back bleeding by compressing the pads and forcing fluid back to the reservoir(to be sure there is no air in the system), to no avail. i have friends with road kings and their brake stops out like mine used to. i have no trouble stopping, but it is a bit unnerving not knowing where the brake is going to catch.

 

sometimes no matter how you bleed the brakes, that dang air lurks in there. I have had this same problem, and an old trick is to pump the lever a few times, and then bungee or strap the lever tight to the handlebar and leave it overnight. Give the calipers, lines etc a gentle tap with a soft mallet to loosem any trapped pockets of air. This allows it to float up the lines at it's own speed. Might need to do it over a night or two.

 

My thought would be that something is leaking down. Either the calipers (1 or both) or the master cylinder.
Tiny air bubbles would give a less than firm feel, not cause the lever to pull all the way back.
If the calipers and master cylinder have never been rebuilt then my suggestion is to rebuild all of them.
Also check the brake lines for swelling.

 

Just for the heck of it, press the pads all the way seated.
on one side, put a medium screwdriver between the pistons, pump and make sure both pistons come all the way out. Clean exposed pistons with brake clean and a brush.
Do other pistons and repeat for the other side.
I do this once a year on my 05 ultra.
Nice, firm and short brake lever throw.
Unless you cracked a line open or replaced something in the hydraulic system there should never be a reason to bleed a closed system.

Clean all 8 pistons, I use a little sil glyde on the pistons with a q tip.
I'd bet they feel like new again.

 

Mine is similar on my 03 RKC. I can pull the lever back half way before it catches. I never have to pump them up as its always there. I replaced the pads and extended the pistons and cleaned them accordingly. Still the same. I took it to the dealer for a brake flush and when I picked it up, the lever would engage the brakes like you said with the slightest of movement but after a while it wen back down to half way. I too have no trouble stopping but would be interested to know what to try. Most other bikes I have seen haven't done this.........yet.

randy

 

If you haven't flushed the brake system. Brake fluid absorbs moisture and should be changed at least every couple of years. I would do that as well as check to see if the system leaks down. If you hold the lever firm does it slowly compress towards the bar?

 

Pad wear and dirty caliper pistons are likely culprits.

 

Yours is a common problem - despite your best efforts there may still be air in the system. There is also a Sticky in the Tech Brakes section on solving the 'soft pull' you have, which may be sticky pistons. Salvation is at hand!

 

if i need to flush the brake system, i am inclined to go to dot 5 (silicone) fluid, there was a problem with my old 76 superglide brakes and converting to dot 5 was part of the fix. i'm pretty much a fan of dot 5 as it has a higher boiling point and repels moisture. other than cost i don't know why h d didn't go to dot 5 as a standard fluid. any comments???

 

It is said that DOT5 aerates due to the action of an ABS system pump, which is why it has been dropped. I had a new '74 SG and have to admit I had no problems with bleeding it. I don't recall if I used DOT3 or DOT4.

I have firsthand experience of mixing DOT5 and DOT4 and the results ain't pretty! The swap should be fine if you strip and clean the system of all traces of the DOT4, otherwise they react and create a disgusting corrosive jello over time. Not good for the brakes or bank balance!