Love this web site
Thanks for all the insight and ideas
Dick has provided a wealth of information.
Keep in mind that adding the power beyond conversion sleeve to your loader valve also requires you add an additional tank return hose to the other outlet port. The hydraulic sump filler is often used to dump that oil back into the system.
Converting the loader valve "fixes" that plumbing but you still have a vanilla open center valve on the post pounder. If you simply daisy chain it off the PB port on the loader valve you have the same "tank return used as power beyond port" issue on the post pounder valve. If you want to "fix" that misconfiguration you need a source of constant flow pressurized oil for the pounder and a direct return to tank circuit for the exhaust oil.
I will repeat my earlier suggestion - first convert your loader valve to PB and then purchase a 4 way 3 position single spool valve with its own power beyond port and daisy chain it off the loader PB. You will need to run (tee) a tank return from it into the tank return on the loader valve - this will be used for your low pressure outlet from the pounder.. Put quick couplers on the work ports of that rear remote valve and you have a properly configured set of rear remotes to use for the post pounder hookup or anything else that strikes your fancy. You can even go crazy and purchase a 2, 3, ... spool valve and add multiple remotes for all of the other things you have always wanted like a hydraulic top link - real handy with that post pounder
Here is link to a suitable single spool valve - no affiliation with Summit - its just inexpensive and you can order it with a power beyond sleeve ($25) and a single position detent ($20) as options. They have multi-spool valves for not a lot more and if I were doing this I would opt for at least one additional spool.
FREE SHIPPING Monoblock Hydraulic Directional Control Valve, 1 Spool, 11 GPM
summit-hydraulics.com
Dan