HLR is driving me crazy

[Thescottsman]

ok i have posted here before but its been so long figured better start fresh, dozer has been out of operation for a long time- brief story, dozer is a JD 450D was excellent would spin the tracks tore it down due to a horrible oil leak,(seal came out from the oil pump tube), had the little mystery ball drop out upon repair, we have put the ball in under/over/behind even not at all as it appears our cover was never drilled for a ball(not sure why it was in there) cannot get the pressure over 60psi with shims, adjusting the clutch pedal ,ect. have followed the book to the T and still only 60 psi. we stacked so many pennies that you could barely screw the plug back in on the regulator valve, no change. we are determined to get this thing fixed as we need it around the farm... JD dealer has been no help all those guys long gone by now. what are we missing when we pushed the tube in for the oil pump could we have covered a hole up? honestly at a lose , we have pulled the engine 4x and rechecked lots of things but no avail. any help would be appreciated