We have been noticing a slight leak on the passenger side front brake line. Where the line meets the hose. We have also discovered a leak further up the line as well. After a very slight turn of the flare nut wrench, the brake line crumbled into a rusty mess at the connection.
Our question is: how hard is it to replace the front brake lines on the 1983 CJ7??

which brake lines the flex lines or hard lines attached to the frame???

Not hard at all you will need all the tools for cutting and fitting brake lines and can of PB blaster and time. You will need to buy a couple of lines so you can practice but its not hard its just time consuming and boring work. I will suggest doing all the hard brake lines that look bad and getting a set of new extended steel braded lines. It won't go to waste since most life kits dont include brake lines.

you can buy all prebent line that are an extact fit but they cost the most. the hardest part it getting the old stuff apart. Welcome to the CJ world

get one from a 95
it has the dual diapraghm booster and master cylinder vs the 94 and before single

Go here for prebent lines.

http://www.rightstuffdetailing.com/2004_pdf/jeep.pdf

the only brake line flaring kit that I found that works 100% is the snap on kit. the ones that you get at the auto store are junk. Also if you want to stop on a dime, go with a E350 MC and booster.

Ok these are going to be dumb questions so bear with me please...I'm
doing all the work myself and brake lines are a first..

If I choose prebent lines will the fittings fit an upgraded MC & booster and proportioning valve?
On that note...I see that prebent come for power or standard disc brakes...can I assume with the booster it will now be power brakes?
And what difference does power or without make when ordering...fittings, line strength??

If I go with bending my own...what kind and diameter?
Quadratec has tubing kits but in 3/16", 1/4", etc.

Since I'm a virgin at the brake thing...what MC replacement will get me the best stopping power with the least mods?...I'm hearing 95 yj or the one
from the Ford.

YJ Master in CJ
http://www.jeepsunlimited.com/mambo2/index.php?option=com_content&task=view&id=42&Itemid=30

Apparently you can get a gm master and it will bolt up to a cj
"With a CJ the solution is to go to a GM master cylinder from a vehicle with 4 wheel discs (usually a 79 Pontiac Firebird) "
from
http://www.4x4wire.com/jeep/tech/brakes/yjmc/

here is the same write up that sonofsam02 gave you but more detail write by the same guy. http://www.bustedjeep.com/projects/yjbrakes.asp

Bustedjeep.com has some good write ups I have meet this guys and they have build some great CJs.

I went this route http://cgi.ebay.com/ebaymotors/1974-1986-JEEP-CJ-SERIES-POWER-BRAKE-BOOSTER-ASSEMBLY_W0QQcmdZViewItemQQcategoryZ33566QQihZ001QQitemZ110250406849QQrdZ1QQsspagenameZWDVW

This guy will help you out if you have a problem he knows brakes inside out and upside down. He will talk you through any problem even if you did not buy anything from him. Great Guy
http://www.vancopbs.com/

Good luck these things take some time but it worth it.

Awesome...thanks everyone for all the info...

Checking into my local pick & pulls for brake booster & mc from 95 YJ to go on the CJ. Getting asked if I need it to come from a 4 or 6 cyl. Does it matter what engine it comes from? I've done the searchs and can't find the answer.

Autozone says:
that it needs to come from a six cylinder.
Its the master cylinder with the plastic resivoir on top instead of a metal one