I need a hydraulic flow tester to test pumps on my bobcat excavator. I am most likely never going to use this tool again or at-least very rarely. OTC makes the tools for right around $3000 and just seems unjustifiable for me to spend that much on a relatively basic tool I will never use again. I found a flow tester on ebay for about 600 but it does not have the restrictor dial. Has anyone ever made there own flow tester or modified the cheaper version to have a restrictor?