7040 hydraulic problem

hello all, new member, having trouble with my 7040s hydraulics, specifically piston pump. a little backstory, hydraulics have always felt sluggish, so i flow and pressure tested the pump and it was low (5gpm flow @ 2000psi, max psi 2100) so i bought a used pump but was not much better (10gpm @2000psi, 2200psi Max), i sent the original pump away to be rebuilt while i had the spare on, and the rebuilt one just came back, put it on, tried it, and it still felt suggish, so i put a flow tester on it, and the results were 13gpm @2000psi, 2200 max psi. now hydraulic guy said they bench tested it, and it tested 20gpm @ 2000psi on their bench, and max psi of 2300, where or how could i be loosing that much from being on the tractor vs on a bench stand? ive tested direct from the pump by the way, shimmed low pressure standby compensator with recommended washer springs as per the book, i thought maybe not pulling oil enough, but filters are new, checked the anti drain check valve and its all good, about to check 25psi bypass above RH filter to see if theres something there, could there be anything else im missing? how many high pressure compensator shims should there be? thats my next check. this has been driving me crazy since august

those flows and pressures i listed were direct from the pump with the compensator shimmed straight from the test procedure in the book, bypassed the rear remotes all together

Are the levers going all the way to detent?      MACK

A related story..

We have a 7050 that always seemed to have poor hydraulic performance since we had purchased it. It had about 4000 hrs when we got it with a rebuilt engine. The dealer assured us it was a "good" tractor.   I had changed some of the hyd lever cable ends that helped some and turned the flow control, but still it was a slow machine.   The only glimmer of hope was once in a while the hydraulics would really work! Albeit just for a second or two. Finally, I took those cables off and went to Princess Auto and bought two push pull cables with slightly larger clevis ends and modified the mounting bracket on both ends making it finely and accurately adjustable and easier to push. No more slop in the levers. The hydraulics work better than new!   

There was just a little too much slop in the cable ends where they mount into the levers and the cables themselves are easier to push/pull with a slightly larger diameter cable. That's why we couldn't get the flow out of the hydraulics. I too, considered the pump but started with the cheapest thing first.

I should of done it 20 years sooner. Now, no one complains about the hydraulics on this tractor anymore. They're fast!