I will be adding extended brake lines soon and need a little info. Do I have to drain all the fluid? It's been a while since I've bled brakes, are they all the same or anything special about the jk? I will also extend the abs wires. How many conductors are in this cable?

 

When I did my brake lines, I did not drain the system. I just made the switch quickly using my thumb to stop the flow when necessary and kept an eye on the fluid level in the MC. Bled normally.

Haven't done the sensors but I believe they are 2 wire. The sensors are pretty long in the first place so you may want to droop your axle and check first.

 

I just did mine this past weekend. I used a set of vice grips to pinch the stock brake lines close to the caliper to keep as much fluid as possible from draining. If you are doing this by yourself, you will lose most, if not all, of the fluid in the caliper when you try to get the copper crush seals and bolt lined back up to reinstall into the caliper. I also put my thumb over the stock metal brake line ends on the frame when I did the side opposite from the caliper. Regardless of what you do, you will lose some brake fluid. After swapping out all four lines and bleeding (I used a hand pump vacuum bleeder), I was just below the min level in the brake fluid reservoir, enough to make the brake warning light on the dash light up. I filled the reservoir up with new fluid, and I've had no issues so far this week. Just have the correct wrenches ready to go when you do it. I think it was 12mm, 15mm and maybe a 17mm (I really can't remember because I did a lift as well that day) wrench for all the connections and bolt for the caliper. 12mm and 17mm (if used) for the end away from the caliper, and the 15mm was for the caliper end bolt. I'll check once I get home and update this post with the correct sizes I needed.

I did not touch (extend) the ABS lines. Just cut the fasteners from the old brake lines. They are pretty long already. I did zip tie the ABS lines to the new brake lines though.

 

Not sure on the JK but some ABS wires are shielded I would check into that before splicing

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Helped a friend repair one of his that was damaged on a '12. It's just a pair of ordinary wires.

 

Whoa, are you running 18" coilovers? It is very rare that someone ever need to extend the ABS lines. Also, the front brakes lines are the same. Get rid of the metal bracket and you have all kinds of length.

The rear often does need extended brake lines though. My advice is to not let much fluid out. Some people don't have issues, others end up at the dealer paying $200 for them to bleed the lines with the star scan tool. And there are some that for unknown reasons, never got the brake pedal feel back.

Best method is to have everything ready and then disconnect the line at the frame and have a buddy plug the hard line with a finger so no fluid drains. Take the new line and attach to caliper, open bleeder, and use plastic syringe to push brake fluid into the new line until it comes out the bleeder (that way there is almost no air in the new line when you connect it.). Then connect the new line to the hard line. Repeat other side and then bleed the system.

 

Just an update as promised. The wrench size I quoted above were correct. 12mm for the factory hard line connector, 17mm for the extended brake line that connects to the factory hard line, and the 15mm is for the bolt on the caliper.

 

When you remove the stock flex line just put the little rubber cap from the bleed screw over the open hard line double flare. Will seal it up so the reservoir won't drain until you thread on the new line. Attach the banjo end first, then carefully thread the new line up to the hard line flare. Just hold the flex line hex steady, tighten the hard line fitting only and you wont get a twist in the flex line. On post 2011s the front flex line is usually long enough, just get it loose from the bracket on the spring bucket. The ABS sensor cable is longer on the later JKs too. Just leave it clipped to the stock line and you'll be cool. You can carefully bend the frame side metal part of the stock line down a bit and get rid of the potential right angle crimp in the line at full droop. You can also use late front brake lines in the rear by swapping them side to side, clip off the ABS line retainers.