John Deere 4020 has low flow.

[Hilltop Evergreens]

Hi Im working on a 66 JD 4020 synchro and it has about 7gpm flow at the outlet.The other day it had 15 gpm and seems like it fluctuates a bit from time to time. It has a loader and it was super slow but then other times its not bad. Also the steering is harder to the left and seems normal to the right.Is this connected? I checked flow from rear pump and have 6gpm .We put a rebuilt front pump on because we had one sitting here and made no diff so original is back on now. The rockshaft cover is off right now and that 4 bolt plate is fine and tight.Any clues? Thank you to anyone

 

[wore out]

Hi Im working on a 66 4020 synchro and it has about 7gpm flow at the outlet.The other day it had 15 gpm and seems like it fluctuates a bit from time to time. It has a loader and it was super slow but then other times its not bad. Also the steering is harder to the left and seems normal to the right.Is this connected? I checked flow from rear pump and have 6gpm .We put a rebuilt front pump on because we had one sitting here and made no diff so original is back on now. The rockshaft cover is off right now and that 4 bolt plate is fine and tight.Any clues? Thank you to anyone

How is the loader plumbed to the tractor, plugged into the remote couplings, or does the loader have it's own valve?

If it has it's own valve, is it the correct, "closed center" type of valve, and where is the return flow connected to the tractor? (Needs to enter the return circuit to be directed to the hydraulic pump charge circuit.)

While the total hydraulic pump flow is supposed to be 18 GPM the rated flow at each SCV is more like 6 or 7 GPM.

As to the steering, likely the steering valve needs to be overhauled (or at the very least needs to have it's valve adjustments reset).

 

[used red MN]

Hello Mark welcome to YT! Have you checked the pickup screen behind the filters, is it clean?

 

[Hilltop Evergreens]

The loader is plugged into the remotes. And i believe the 15 gpm was right off the pump so maybe we don't have as big a problem as we thought. Unless there's a piece of dirt somewhere that's plugging a passage.
And yes the screen is clean and new filter and oil. Thanks for the info . I think I will play with it some more when I have a chance.

 

[buickanddeere]

How long are you holding the clutch pedal down ?