I need a refresher on how to mechanically center the main pumps on a closed circuit system,the main cylinders or actuators tend to creep.

I would do hydrauliclly before doing it mechanically

Explain?

Bisley, he means to put it on a test bench and flow test it hydraulically.  I was told that this is really the only way to do it perfectly.  If you want to play with it though, I believe the adjusting bolt is on the side of the controller (the piece that is on the side of the pumps and is perpendicular to them). 

I will try to explain the best i can Get at least two 60 bar gauges and connect them to one side of the servo turn the pump on the gauges should build to the same one both gauges its not that important what the presssure builds to as long as there the same pressure. check both sides of servo if there is a difference i think its a 10mm wrench and a small flat head screwdriver very cautiously loosen jam nut and turn screw in appropriate direction to center servo the movements are very minut adjust untill pressures are the same and check if cylinders are creeping if that corrects it your good if it does not you could have a bend rod on your drive unit or the servos are mechanically out of center and i would not attempt if i were you probably be better to send out and get bench tested but try those adjustments depending on which drive unit you have its not uncommon for those arms to get bent. let  me know what happens if you run into trouble email me good luck

allen bolts on the side are for mechanical centering you shouldnt have to do that the drive unit is in the middle of the servo housing

Alright,one adjustment screw on the middle of the servo housing,by chance do you know which port to go to on a Putz with a centralilized port location?M2/5?

I believe its m2 5 the one with the circle and the line through it how old is this machine

2007,I went and looked at the gauge lines coming out of either side of the servo and they were about twice as big as the others.I think they led to M7.Going to give it a whirl today,thanks pumpit.