the lining of the hose probably peeled away, and is blocking the thing up, you wont see it externally
you can easily see the brake hose stretching from the wheel well to the brake caliper. you might look for cracking or oil soaking it.
(i changed my brake hoses without jacking the jeep up at all. It does give you room to work, but it bugged me being under a jackstand in a parking lot, with ricers and motor cycles screaming by.)
There are 3 problems to overcome when taking apart your brakes.
breaking the fitting loose on the steel line
breaking loose the bleed screw]
breaking loose the hose from the caliper
all of the connections are going to be seized, at least partly corroded, and made of soft metal you could easily destroy with one slip.
i use a vice grip pliers over a flare nut wrench.
i also NEVER use PB blaster or any oil based penetrating oil on brake fittings. you get any of that into your brake lines, and it will swell the rubber seals throughout the system
use brake fluid as the penetrant.
I used cheap as flare wrenches and crushed them in my bench-mounted vise to make them fit tight as hell, then squeezed them around the brake fitting with vise grips. the fitting comes out perfectly, zero slippage.
but, if the fitting is seized onto the brake line it may twist it. That can be unavoidable depending on how rusty your heep is.
yes, there are hopeless scenarios where you HAVE to destroy another part to finish the job. be ready for that one.