73 GMC 2500 Hydroboost/locked brakes after hose replacement

[73FrankenTruck]

So as I'm cracking into this new project, I've hit a stop that I cannot get around:

History: 73 GMC 2500, 454. Converted to 1-ton dually. truck arrived to me with zero coolant. Replaced heater core, thermostat, all coolant related hoses, flushed coolant system. Went for test drive. Filled up gas tank. Truck drove, turned, and stopped fine. As soon as I (parallel) parked it, saw smoke from under hood. Driver side inner fender had fresh fluid on it. Upon further inspection, the hose from hydroboost booster to the steering box had a pin hole leak.

What I did/what happened: replaced aformentioned hose. Topped off power steering fluid. Started truck, turned lock-to-lock about 40 times while repeatedly pushing brake pedal. Fluid level was same. Put in gear...brakes are locked up. I tried the lock-to-lock deal again, same result. I've researched threads on here, but what i've read always seems to involve replacing the booster. I just swapped a hose. Everything seemed to be working fine.

Any ideas? Am I not doing something correctly? Thank you for any insight.

-C