Once you start getting above 3" of suspension lift on your TJ, I highly suggest replacing the brake lines with longer, extended brake lines. One option you have is shelling out some money for aftermarket extended "stainless steel" brake lines. However, another option is the readily available Dorman EPDM rubber direct replacement, extended length front and rear center brake hoses (4" longer than stock). No special washers or other parts required.
The part numbers for these extended length front brake hoses were posted by Blaine in another thread.
Front Left:
https://www.amazon.com/dp/B00IY2CHHK/?tag=wranglerorg-20
Front Right:
https://www.amazon.com/dp/B00IY2CBTY/?tag=wranglerorg-20
Rear Center:
https://www.amazon.com/dp/B00IY2C63K/?tag=wranglerorg-20
Once you're all done, you'll need to bleed your brakes. You'll need a container of DOT3 brake fluid for this. To make bleeding the brakes much easier, I highly recommend one of these
vacuum brake bleeding tools. I have one of those tools myself, and it's paid for itself multiple times over. It makes bleeding your brakes so much easier.