Hey guys. I've searched multiple forums and haven't quite found the answers I'm after, sorry if this has been talked about before.

Planning on doing a bar swap in the next 2 weeks on my '18 FLHR with ABS to 1.25" LA Chopper 14" bars. Going to get their extension kit to go along with it (wires, clutch line, brake lines). I have 2 questions--

Am I going to be alright doing the brake line swap without having to mess with ABS module? Or do i need to take this to the dealer to have them "cycle" ABS for install?

Also, which brake lines do I need to replace exactly? I guess in my head it should only have to be the one from the bars down to the ABS module. The kit includes multiple lines and is quite $$$. If I could get away with separately purchasing things to save some cash that would be sweet.

Thanks for any input fellas

 

I have 14" KST Straight Jacket bars on my 2021 FLTRXS. All wiring and brake lines worked fine. Clutch cable also but you have a juice clutch.

 

I have discovered that some 14" bars will work (KST included) however i dont like the way the cables look "stretched". Just personally would rather have them more relaxed and be able to better contour with the bars

 

You can bleed brakes without actuating the ABS module.

 

True if the OP is just bleeding the brakes. Pretty sure he's replacing, at least, the upper line with the taller bars. Doesn't that go to the ABS module?

 

Yes, the line is upstream of the ABS module, but the fluid and air will bleed through the ABS module, just like you'd bleed it out after replacing a line in a regular vehicle.

Now, if someone actuates the ABS module while bleeding it, bringing air into the ABS system, that would be a problem. So don't cycle the ABS while bleeding out the brakes from installing the new line.

And if it's all freaky uncomfortable to you, have a dealership or shop do the job. Nothing wrong with that either.

 

If you're just replacing the upper brake line you can also reverse bleed

 

I think you had better understand how HD ABS system works before administering advice. How on earth could someone activate the ABS while you are working on a stationary bike unless the ABS bleeding software was at hans? If you did have the ABS bleeding software and knew how to use it there would be no concern about introducing air into the system.

Brake fluid does not go through the ABS module like your car, with HD there is valving involved . If you do manage to get air in your ABS module you may not know it and when the ABS pump activates you may find out that you have no front brakes when you need them most in a quick stop.
You can carefully replace the brake line and let the air find it's way to highest spot which is the master cylinder. FatBaggers make a brake line extension that has a bleeder at the highest point that works on this principle. FB is an extension so there is no need to remove the line from the ABS module.

 

Let me better clarify my words. There is a path the fluid goes through normally from the master cylinder to the caliper(s). As long as one doesn't do interesting things, replacing the upstream brake line will not introduce air into other parts of the brakes. Particularly the pump and reservoir, as those are blocked off by solenoids or valves. So conventional bleeding techniques will work adequately. So too will reverse bleeding.

If one manages to actuate things in the abs module while actively bleeding air out of the system, it can introduce with air into the abs module components, with generally deleterious effects. As well if one cleverly removes and opens other fittings or components of the ABS module, lets things drain for days, etc. In which case the full ABS cycling while bleeding/purging/flushing will need to be performed. Hence my semi tongue-in-cheek comment about not cycling the ABS while working on the brakes doing a simple brake line replacement. Don't ride it, don't cycle the ignition, don't perform ABS tests, don't play with jumper wires, etc.

Yes, using a bleeder at the top of the line at the master cylinder works. You could also simply reverse bleed and push the air right through the master cylinder and into the reservoir. And you can do the messy fitting crack technique to bleed there at the master cylinder. For less money than the FB line, you can simply buy a banjo bolt with a bleeder, they're usually less than $20.

And as always, if all this is icky or scary sounding, don't do it. Send it to a dealer or shop and have it done professionally, and have the full ABS cycling done to absolutely ensure all air is completely purged from the braking system. There is nothing wrong with this approach. It can even be done after you install the line and are unhappy with the bleeding results for whatever reason. Won't be like they haven't seen it before.

 

On the OP’s bike, the brake line from the master cylinder is one line. It does not go to the brake calipers first. It goes directly to the ABS module. He wants to replace that line with a longer one. That includes disconnecting the line at the master cylinder and the ABS module, then reversing the process to install the new longer line.

Unless I’m mistaken, the service manual says that the brake system will need to be bled by following the procedure in the service manual, which involves using the DTII to activate the ABS module. Of course, there are aftermarket devices that can be used to activate the ABS module if he chooses to go that route.