it looks like that is a sliding caliper so if you hooked up the hard line for the brakes then everytime you apply the brakes you will be flexing the steel line when the caliper moves. Not a lot but how many flexes can the line take before it breaks? Might want to look into short flex lines. Just a thought.
the rear disc have a short rubber flex hose between the caliper and hard line. I'v got the whole rear end out from a grand cherokee just the other day. Brakr cables and all.:-d:-d:-d
