I have a 2003 Road King Screamin’ Eagle with a 103 inch engine with 15,900 miles. The problem I have is with the front brakes. The problem is that the brake lever will pull about half way back before it resists and the brakes are applied. Every previous bike I’ve owned, both Harley and others, the brake pressure was right there when pulled within 1/2” of starting the pull, allowing one or two finger pulls without hitting your other fingers that are controlling the handle bar with my right hand.

I’ve had this to my local dealer twice. The last time they replaced both front calipers, replaced the front brake pads and bled the brake lines. It worked temporarily, the brake pull was firm as soon as the lever was pulled but after about 2500 miles, the problem has arisen again. The front brake lever once again pulls over 1/2 way before actuating the brakes. If you really have to grab a handful of brake, the lever can come all the way to your fingers. Ride any rice burner and the brakes apply as soon as you touch the lever.

I have Dot 5 brake fluid installed, the 2005 and newer have Dot 4, which the dealership says Dot 5 compresses easier than Dot 4; hence the newer bikes don’t have this problem. I was always taught that fluid is fluid and it won’t compress. I’ve tried newer bike brake levers and they are as I would think mine should be. Should I replace everything in the front brake system and install Dot 4 as the dealership suggests or could this be a master cylinder problem? It and the hoses are the only things not replaced. Any replies would be appreciated. Thank You. Bob

 

Sounds like a MC problem.

 

Sounds like you're getting air in the system again after 2500 miles like you say. Once the system is bled and working properly , only thing that can make it go back to where it was with the lever pulling up is an air cushion in the system. If you bleed it out again and find air, you may want to check into the master cylinder like stated above.

Here's some info on the various fluids... https://www.hdforums.com/m_68186/tm.htm

 

I replace the master cylinder about 4 weeks ago and have bled the system 4 or 5 times, 3 by them and I've done the rest with a bleeder. The dealership is perplexed about this to the max. You can just imagine how I feel about it. Squeeze any 05 or 06 front brake and it is firm and nice, they say because they both have Dot 4 fluid. Any more ideas? Bob

 

Try this...

Turn the bars left so the MC is level, pump up the brake lever and tie it in the squeezed position overnight. In the morning, tap around the master cylinder with a hammer handle wrapped in a cloth so you don't mark anything while watching inside it for bubbles (cover off) . See how the brakes are then. Let me know.

 

TC, some of the most simple things seem crazy throughout life. I did as you said, the brake lever goes almost to the throttle grip and used a wire tie to hold it. I will tap on it tomorrow morning and see what happens although I don't think this is it. I'll be the first to admit wrong if I am. Thank you again. Bob

 

Yeah, been noticing mine getting soft after riding for a bit, think that is air too? Seem to have a full mc.

 

Hey guys I'm having the exact same issue. I recently purchased a 2001 RKC w/ 4900 miles on it. The bike appears to be in mint condition, except the front brake lever is soft. I've bleed both front cylinders 20 times or more, no change....no better no worse.
I tried bleeding the conventional way with gravity feed and I've tried vacum using a mighty-vac. The system uses dot 5 the same fluid that's in my 2005 Deluxe uses (which by the way has great lever pressure). I also wire tied the lever over night and tap on the lines, tee and mc....still the same.

After reading several threads on this subject I'm started to wonder if it could be the master cylinder. I understand the MC are rebuildable. My question is - has anyone had the same issue and resolved it with a MC rebuild and if so, what all does this involve ?

Any help wouild greatly appreciated.

Chris

 

TC I did exactly as you said, the front brake grip was held with a wire tie all night and today and I just loosened the master cylinder cover and tapped it with a rubber grip screwdriver--not one bubble. Any other ideas to try? I appreciate your professionalism, don't quit on me now. To Bare Minimum, I have been told by many Harley Service Techs that the 2005 models have Dot 4, not Dot 5 like you indicate, the reason that they have greater lever pressure like you indicate. Check for sure before you add or bleed that 2005 bike. I've replaced, not rebuilt, the master cylinder and it is still soft. Thank you. Bob

 

I don’t know if this is what you have going, but....

The pads should ride against or very close to the rotor. If the rotor is not completely true it can force the pistons back into the caliper as the tire turns. It then requires more lever movement to bring the pads against the rotor before the brake applies.

This would cause excessive lever travel after riding it. Once you applied the brake, the lever travel would stay firm if the bike wasn’t moving. Once the tire made enough revolutions to push the pistons away from the rotor, the lever would again have excessive travel.

Good Luck,
Doug