Success. I increased the pto speed to 1000 and it is digging.Both the gears and case can wear over time and cause a loss of pressure.
Most pumps are not rebuildable, too much wear happens an the tolerance becomes to great.
Does your pump have a gear box attached to it or just direct drive from the PTO?
If it doesn't then that's your issue, it's probably needing a 1000 rpm just to work right.
The stock pump had a gear box to bump up the PTO speed to 2000RPM driven by 540RPM PTO.
I have no gear box. I have it hooked up directly.
It was unclear to me when looking at my parts manual if all the pump models used a gear box. It looked to me like the gear box was only used with the vane pump, and not my gear pump, but I must have been wrong.
I think my pump is warner pump P328EJ57L02 - can't find any info on the web.
Thanks