354 LE Hydraulic issues

Hello all. I am having some difficulty with my loader and backhoe on my tractor locking up. I hadn't used the tractor for almost a year when this issue happened.I tried using the backhoe and was able to move the hoe back and forth and fore and aft no problem but when I put down the stabiilizer pad it would lock up the hydraulics( meaning that then nothing worked or more accurately I could move something incredibly slowly. It seemed as though something(check valve ,pressure relief valve ) I'm not sure what but it was stuck.This happened a few times and then an hour later pressure would seem to bleed off and I would be able lift the loader and move the hoe around until I put the pad down again and it would again lock.

I thought maybe it was in the Backhoe circuit(Woods 7500) so I removed it from the hydraulic circuit and plugged the hoses together to keep the open spool circuit and thought at least I could use the loader. All was fine when I went up and down but  that changed when I tried to curl the bucket. Same problem hydraulics locked. So I finally decided to call Ron at Ranchhand for the Loader Valve upgrade(thanks Ron)thinking the problem may be in the valve plus its been leaking for years.Sorry to say that that didn't do it either.Also when this happens it appears that the pump starves for oil as it gets hot.I basically down to the issue being either the pump itself or nwhere the return goes into the lift box whether anything there is sticking.I 'll buy a new pump if need be I just don't want to do it and potentially kill another.I do have one more test as I am going to remove the spin on filter and housing to see if that helps as I have read that sometimes the checks stick.Thanks for any help and sorry for this being so long .Also in case I still don't have any luck does anybody know of someone who works on the Jinma Tractors in my area.I live in Lagrange(Dutchess County , New York)