Not certain what lines to advise you to begin with first or if you should just remove all and work from the rear forward. Would like to hear another member who has done a jeep in its entire as I have only done a car or two but except for a little different routing the job is similar. I am personally all for draining and replacing all the brake fluid since brake fluid and power steering fluid are the two most neglected fluids on any vehicle. Old brake fluid is possibly full,of moisture and causes corrosion which contributes to decay of lines through the seams. External rust is what is most responsible for brake line demise bit old fluid which reaches boiling points many cycles over year after year is slow death to the braking system. ABS systems are the only systems difficult to bleed but non-abs are easier if all the bleeder screws are able to open easily. First , make certain you can open all the bleeder screws before you attempt any further work or you will possibly cost more time and possibly more money. Of a bleeder is difficult to open , allow penetrant to soak for as long as necessary and if locking pliers are needed , use the shank end of a drill bit inside the bleeder screw hole to try to prevent the bleeder from crushing and thereby snapping off. Make certain the bleeder hole is clear of debris. Once all bleeder screws open successfully , that fear is eliminated. I use anti seize compound on the threaded nuts on the threads and on the tube where the nut spins on to prevent ( or try to) seizing for future removal of need be. Always got to think you may have to remove something again someday so,good to make life easier if you can. For example ; water pumps. Don't be afraid if the master cylinder is bled dry , you can bench bleed it if need be. ABS is the only problem that can hold you up,from easy bleeding . That , and a partner that dosen't cooperate with the pedal.pumping.
A word about this method of bleeding ; although this method is tried and true , cheapest and fastest ( usually) , I must ask what condition the master cylinder , wheel cylinders and/or calipers are in . Old seals inside of these cylinders will breakdown soon due to excessive travel of the internal Pistons moving further than typical in regular travel with regular pedal,effort. The master cylinder being the first victim . Over time , corrosion builds up inside of these parts largely due to moisture and causes internal corrosion. That damages seals and causes leaks internal and external. Master cylinders lose their ability to produce adequate pressure and wheel,cylinders and calipers may blow out. I'm hoping this will NOT happen to you bit want to prepare you as I've seen it too many times (now I know why people lease cars). Don't want to,scare you or intimidate you , just prepare you. I would first want to be sure the master is bled before going further when bleeding time comes. Once the master is done , the rest of the system is done as per the manual . Right rear , left rear , right front and left front. Clips and hangers that secure the lines to the chassis are notorious for,corroding steel lines especially metallic clips and hangers . See what is available to,replace,them in non-metallic. I swapped factory bent lines from one car to another and it was tedious but wasn't impossible , just very dedicated. Plan your routing ahead to have a master plan before hand. Cross members , body curves , exhaust , axles etc. will be obstructions bit planning will help. Hope this helps . Best of luck and best success .
