I R&R'd the o-rings on the spool in the power steering valve of my 1958 310B Gas Utility to stop a leak on an otherwise normally operating power steering. The o-rings are the high-pressure type from Case. When put back together, filled with power steering fluid & turned lock to lock a half dozen times, I had no power steering. As the Eaton style belt driven pump was original, I fingered it as the culprit, so it was replaced with a new gear driven pump from All States Ag Parts and two new hoses, still no P/S. I took the relief valve in the valve body apart, which was clean & no scoring on the ball, back together, still no P/S. The valve body/cylinder is very clean & has all parts in the proper sequence as per my 1960 Case 310B Service & Parts Manuals. Any suggestions will be greatly appreciated, thanks!