Hydraulic pump on late 4020

larryanderson

Well-known Member
On my late 4020 syngro that we use on auger and other jobs such as haying it seems like when I have to use clutch my loss of hydraulics and steering time is getting shorter.It has around 10K hours and has never been worked on.I assume front pump is getting weak .Would that be correct assumption?
 

More than likely there's an internal hyd leak robbing pump output. Check temp of hyd control valves with a laser thermometer for higher than normal temp.
 
Just wondering, I would think the rear pump is wearing out. I really don't know. Any comment anyone? Paul
 

Has the transmission screen ever been checked and the filter replaced ? Any difference when the three point hitch is set full depth ? Is the power steering hot even through the tractor is sitting stationary ?
 
I agree with Tx Jim's thinking. I have had far too many pumps brought to me that were not the cause of the issue.
 
The trans pump may be weak but the PTO valve is probably leaking through robing your stand by pressure ,,caping the supply line to the valve will prove this,,,it's a common issue on console tractors
 
I used to see problems like this pop up after 9,000 hrs. I could almost always guess how many hours a tractor had by the owner telling me about this new problem. Up here where the 4020-4320 was a tillage tractor for years then moved to a chore tractor it toke about 9,000 hrs for enough wear on the brake pads to allow the rivets to start being worn on. This contaminates the hyd. system. Now things start to act up. I like to add a filter to the line just below the clutch peddle to clean the oil before it can get to the main pump. I have found this really helps high houred JD tractors keep going. Al
 
(quoted from post at 07:20:39 10/12/19)
More than likely there's an internal hyd leak robbing pump output. Check temp of hyd control valves with a laser thermometer for higher than normal temp.

EXACTLY.

The oil already "up front" is all the main pump has to work with while the clutch is depressed.

Hydraulic functions are supposed to return oil to the cooler, so the cycle can continue, when "function oil" is leaked "to sump" instead of being returned to the cooler the oil supply quickly runs out.
 
Thanks for the replies.We will finish out season and take it to one of the best JD mechanics I know that has his own shop and get it fixed.Now if we could just get a week or two or more of normal weather.We have been wet all year and just got 3 1/2 of rain we didn't need.We do have large flotation type lugger tires and HRWD on our combine so that will be an advantage I hope.
 

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