Central Saskatchewan Canada | Agent86 - 5/24/2025 21:09
For closed center like 4640 the screw on the pump should be all the way in so it does not bypass oil. I'm not sure if the 4640 has flow control. If yes then open it up. If pressure to high you may need needle valve in line to pump to restrict hyd flow. Orfice would only be used to protect pump from high rpm.
So next how is the sprayer plumbed to control pressure? Can be bypass or throttle. Is your bypass valve closing? Or if throttle is it open? Is pump impeller good and no garbage stuck in inlet?
You use the flow control on the tractor to throttle
Down the pump pressure. Don’t open it all the way up. |
John Deere 4640 brand quick fold 80 pt sprayer hydraulic pump issues
