Kubota KX121-2 Hydraulic pump

Anybody out there know where to get a cost effective replacement pump for a KX121-2. My machine is is only getting to 1500 psi on the right track drive, boom and bucket. I swapped the pump pressure lines and the low pressure problem followed to the left drive, arm etc. I was looking at the parts catalog and pricing the valve plate, pistons, cylinder block, seal kit and the price is getting close to a plug and play unit from Kubota.

Thanks

Update:

The pump has been disassembled, "inspected". The valve plate hade .002" gouging and the cylinder block .001". The output bearing had spalling on the rollers. Valve and block have been cleaned up and lapped, output bearing and seal replaced. New seals and gasket and it's back together. I haven't had a chance to bolt it on and try it so I'm keeping my fingers crossed. In addition, new filters (suction filter was missing) and suction hose. After much research it appears Kayaba pumps of this model aren't supported by any including Kayaba North America with the exception of Kubota. China has the rotating group available however I did not and will not be going that route. I'm always open to input. Stay tuned.....

Repaired. 3000 psi both sides.

Long shot, I understand but what did you do here? I am looking into a 121-2 but it needs a pump...

Great work - bet you saved yourself a bundle!

He was saying that he took the pump apart, lapped the damage out of the pump and reassembled it. As the pumps wear or get contamination in them they will groove the two matting surfaces. They need to be dead flat or it will bypass pressure. If you are mechanically inclined and detail orientated they aren't very complicated.