my guess is the swivel block you are speaking of is a hydraulic hose swivel and the hoses are mounted to a hose reel and that if it is the o-rings inside the swivel block that start leaking,
you are over tightening the hoses. they should be almost slack and not more than 1 spring loaded time around the reel when the hose reel is closest to the swivel block.
Most designs have gone away from a swivel block, and use a hose protector clamp to keep the hoses from crimping as the hose's 'angle of attack' changes as the carriage lifts past the hose reel.