partsandservice
Senior Member
I am always trying to come up with ways to check components after repair and before installation on the cheap. When I repair hydraulic pumps and motors I place gorilla tape over the inlet and outlet ports and manually turn the shaft, if it pulls and push the tape with nothing but air then I know it will pump or turn. Of course this does not work in all applications such as hydrostatic drive pump with intrigal charge pump because you would be only checking charge pump operation. Also there is the tried and true method of air checking transmission clutch packs. I have bulit a Dyno(I use that term lightly because there is no load test) to check the pressure on Cat transmissions I have built to ensure the clutches are engaging as necessary. It is A contraption and difficult to set up. So I had this thought about this about pressuring the clutch packs through the control valve with a potapower to system pressure and then measuring leak off time to establish at least the hydraulic condition of the clutch engagement. The question I have is without the shafts turning would the leakage at the shaft seal rings be greater with the shaft stationary? Please include any other "Dyno" tricks you guys have developed and want to share.