On my naa we just did hubs and what not on we tackled the hydraulics that have always dropped on me. We changed the piston, new o ring and wiper. We put in a new hydraulic safety valve assembly. We did remove the pump from the top plate to clean it up but did not mess with any of the position arm or draft linkage. Wilkes all the reservoirs with oil today and fired her up. After realizing it was in draft mode we began to bleed any air from the system that we could. Once it started to work as it should and all the air was gone it still drops then jumps right back up. Quicker than before but is still doing the same thing s before. We pulled the fill plug and can not see any oil getting by the oring and or wiper on the new piston and it doesn't look like anything is coming from the safety valve assembly.please help I am at a loss. Thank you.