Wd45 hydraulic pump problems again

Well well well here I am again and starting to need nerve medicine with this pump.
I was out sickle mowing just so happily and got done for the day and was driving it home( a 2 mile drive) and heard a pop and looked back at my pressure gauge I have on the outlet and it was over 5000psi ( that’s as far as the gauge will go) and oil started spraying ( still not sure where it was coming) and the control lever would only kick it down to 2000psi when it was all the way down.
I didn’t have far to go so I drove it right into the shed and shut it down and it wouldn’t set the mower down until I turned screw “D” in than it did…
So now I’m wondering what did it do internally to the pump?
Do I dare pull it apart again?

When any implement gets raised to the desired height, you are to pull down the hand lever mid-way to the HOLD position so the pump isn't pumping continually. Also, screw "A" must be screwed into the divot to keep the Traction Booster system shut OFF, which if not done, may have caused the pump to slowly hammer away to high pressure. If the Traction Booster signal linkage fell off the tractor while screw "A" was loosened, this too would turn on the Traction Booster.   Turn screw"D" all the way in and start the tractor (after verifying screw "A" is locked into the divot) and see if the pump is asleep or not by moving the hand lever up/down. If all is good, turn screw "D" all the way out and see what happens. Did you wash out the hydraulic sump really clean while the pump was off the last time ??

I just did what you said Drallis and the pump is asleep with screw D in.
It will now top out right at 5000psi but it settles right down to 1500psi unless I hit the clutch and release than it will go right back to 5000psi.
That kinda confuses me but I’m sure something else is wrong that I’m not seeing…

The unloader valve seems to be opening at 5K. The pressure will settle down and at some point will re-pressurize again to 5K and over and over again as long as the Lift/Lower lever is up when it should be in HOLD.

After the first rebuild,what was your max pressure? When pump unloads it will quickly drop max psi down to that 1000-1500 number. My question is,how much shimming and what was the result? Do too many?

I just pulled the pump and counted 10 shims total.
So I’m going to pull 4 shims and that should put it at 3600psi?

I can't think what it would be, but I wonder as it got got if some dirt came loose or something freed up the unload valve to original working condition. Meaning the extra shims now added too much pressure.

The operator manual has detailed instructions how to set all the linkages. I would do that to make sure everything is adjusted correctly. That goes back to what Doc said.
For some reason the pump was pumping all the time while in the hold position. Somehting is out of adjustment.

Something inside the pumps control box is turning the pump "ON". Screw D (when screwed inwards) is shutting the pump "OFF". Screw D is intended to be a speed control for the pump but it can completely shut the pump off when screwed fully in.