Was taking off my rear brake line when I noticed that it was broken. It's the line that goes to the holding bracket and runs down the side of the vehicles. Where can I get this and is this the line that holds pressure when you brake?

 

You got very lucky that it broke when you were working on it and not on the road.
All your brake lines should hold pressure when you apply you brakes.
BTW, The way the lines look you should really think about replacing them all. If they all look like that I guarantee that you will be having a lot of leaks if you don't change them. You will be better off changing them or you may be heading down the road and have no brakes and wish you did change them.

 

Just get about 8ft of 3/16 steel line from a auto parts store and rip the old line out from rear axle to the valve and replace it.

 

When I was working on my crossmember I noticed it was rusted but thought it was a fuel line. The line is 3/16ths and about 8 feet? They had it for like 5 bucks but it looks like such a pain in the *** to do.