2006 komatsu wb150 pump problems

backhoe has been great. its got 4500 hours and now the hydraulic pump is chattering making alot of noise. im guessing the pump is bad. but heres my real problem. i cant seem to find a reman or a rebuilt pump. the komatsu guys need 4200 for a new one.. ouch. does anyone know of a place i can send the pump off to have it rebuilt. or do i just bite the bullet and get the pump?

2006 komatsu wb150 pump problems