I changed the handlebars on my 93 FXDL, from a set of buckhorns around 10" to a 12" mini ape style. Everything fit but the top brake line is stretched tight against the bike, and I know the vibrations will wear it through, and it looks like hell also. I have measured the old line (I believe it is 21" from fitting to fitting) and just want to know how much extra I should add? I'm guessing 3-4" longer but would like some opinions. Also, my understanding is that I just need to swap then pump brakes while adding fluid to the MC until it works smoothly again?

 

Get a piece of romex and put it from master cylinder to caliper.
When you get it looking like what you want your brake line to look like then lay it out flat and measure it.

 

I use string. It's always better to be longer. That's what she said

 

I wish bleeding the front brakes were that easy.

The new lines will be full of air. Pumping the lever will force it all into the caliper which you can then bleed following the procedure in the manual. The easier way may be to NOT pump the lever, but just tie it back to the grip overnight. The air will work it's way up to the master cylinder and you'll probably have some brake immediately. Still give the calipers a quick bleed to be sure.

 

I tend to use short strokes with lever quickly and watch the bubbles in the master,then a few full squeezes. Once you get those bubbles out you will feel it start pushing the fluid to caliper.

 

Mitty vac. I stand by this. It works great and cuts down the time and you can pick them up for like forty bucks

 

Mighty vac works great, or strap the lever back overnight. I do both. Any other way you do will seem like it is taking forever.

 

Sorta.

Read up on bleeding brakes. Everyone will have their favorite procedure, and most will work fine. There are quite a few YouTube videos.

Now is a good time to just flush out all the old brake fluid. Make certain you use NEW DOT 5 fluid, from a sealed container, which has a purple tint to it. I used a MityVac to suck out all the old fluid and replace with new:



Dual disk brakes are a bit more difficult to get bled, but with a bit of patience anyone can do it. I would recommend going to Home Depot or Lowes and get a length of clear plastic tubing. And gather up a couple plastic soda bottles to serve as catch cans. I also had a velcro bundle strap that I used to hold the lever back.



I also used a small plastic tip hammer and lightly tapped the calipers, fittings, lines, and master cylinder to dislodge any trapped air bubbles. In addition to the manual bleeding, I also secured the lever to the grip and left it overnight. I checked fluid level next day,

You'll know when you have bled out all the air, because you'll have a nice firm feel when you pull the lever back. Spongy=No good. Firm=Good.

Here's a link to a thread I posted when my front brakes where gone: https://www.hdforums.com/forum/evo-c...e-a-brake.html

 

A single rotor front brake should bleed itself, especially if the line is a single continuous one and you turn the bars to the left, so the reservoir is the highest part of the system. Having got fluid through to the bleed nipple, gently and repeatedly flicking the lever should bring any air back into the reservoir.