JD 310A hydraulics making a banging sound?

so I kinda confused JD says my pump is AR101288

but looking online I find other info
http://www.reliableaftermarketparts..../AR101288.aspx

the AR101264 says if I have a Destroke valve which I do on the top plus that destroke side with the relay on it....

what would I have then?

also the hydraulics making funny sound almost like when your water taps make a banging sound shutting valves off

https://youtu.be/Cwa0zac2VFI

and is the pressure in the pump supposed to drop after the backhoe is shut off or hold pressure?
https://youtu.be/XTCIEcgR8CE

JD 310A hydraulics making a banging sound?