If only one wheel is locking the problem is in the caliper or the flex line going to that side. Try loosening the bleeder screw to the locked-up brake and see if it releases. If so, replace the flex line. If not, replace the caliper. "New" doesn't always mean "good".
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!