I bought a 4620 at auction, advertised as a hydraulic pump problem. The front end has had a few pieces replaced, like the piece that connects both ends of the tie rod for each side of the front end and at least one vertical spindle, so something pretty tragic has happened. They said the tractor would perform just fine if the hydraulic pump was bled, and they have installed a little bleeder valve there. The 3pt chatters and shakes going up and the steering is slow is that it is not working properly. So, my questions are, could there be something in the steering part of this tractor, maybe in the column causing the oil to flow through and not building the overall system pressure or does it seem likely that it is just the pump? ? I’m asking this because my grandfather once impacted the front end of a 5020 and had to do column work and that tractor is still out of steer for the first few minutes of operation. Any idea where to start? I don’t like to drop a bomb if it can be in the direction as a result of blowing it up.
You start by changing the hydraulic filters and also remove the suction screen at the bottom of the gearbox and look for debris. I would cut one of the filters and look for metal chips. Then I would check the operating pressure of the hydraulic pump. Then I would do a flow check on one of the hydraulic outlets. If you can’t find the problem I would proceed to a transmission pump flow test, I have seen on rare occasions that the transmission pump gasket has burst and caused symptoms like the ones you describe, but before I get to that, Do the simple checks first. Your main pump sounds like it’s starving for oil. Unfortunately there are several other places the problem could be.