valve slippage leaking seals

[cosworth34677]

ok i got two more hydrulic problems

1. i got a set of valves that work great they move great . and what ever i hook to them move great.....but......
they won't hold, the excavator arm will slowly stat to fall, and i have replaced the little orings in them helped them in moving better bet they still won't hold, even if i take off the servo and try to find the center it still will slowly fall.
is there a fix? this is the version two magom hrc valves.

2. i got a set of valves the will hold and work..... but kind of slow, they always been kind of slow moving even new. but they have this funky leak thing hear they leak around the orings where the shaft on the valves come out of the valve. the shaft that hook took the servo adapter , is there a fix for that? i have replaced the o rings, just not the little plastic wash between the oring and the valve. these are the version 3 valves from magom

both are two- four years old .

any help would great thats