Help wanted. we have taken the linde pump off the CK81 and replaced it with one from a 688, whilst most of the plumbing is fairly obvious the 688 pump seems to have 3 low pressure inputs one being on the lower part of the bell housing. I have the manuals for both machines but they omit the pipes to the lower bell housing. phots of the 688 pump in place might be handy
I don't know where you are from but Poclain excavators have not been sold in the US in many years. A photo of your machine and the kind of pumps you are speaking of might help.