I have a Ford 1700 tractor with a Ford 770 front end loader. The hydraulics were working fine and after running the tractor 8 hours tilling a field and moving dirt with the bucket the hydraulics became jerky and jumpy. If the tractor were to sit and cool down the hydraulics are smooth for the first 15 minutes then they become jumpy and jerky. I have flushed the fluid 3 times and I installed a shaft seal and o-rings on the pump. The loader abd the rear hydraulics are still jumpy. I have installed a 0-5000 psi Guage on the auxiliary service port next to the rear hydraulics speed control. With the control lever in the upper position the pressure is 400 to 500 psi. If i place the kever into the locked notch position i am able to get the pressure up to about 3000 psi. Withe the lever in the upper position should i be able to get the pressure up to the 2133 psi calibration value? If so, could the pump need replacement or rebuilt? Does anyone have a part number for a rebuild kit? I have found i new pump for $450.00.