Korman Trucking

Hi, My dad and I are scratchin our heads over this issue. We put new seals in our power steering pump a week ago, since then its been getting harder and harder to steer. We jacked the truck up with the motor off and armstronged the steering, then we started it up to compare. It was easier to steer without the motor running. We have heard rumors of adjustments on the relief valve or poppet valve. We cannot find either on the truck. Any info would be appreciated to guide us to a fix. Thank You