4000 Hydraulic Pump

   / 4000 Hydraulic Pump #1  


Bronze Member
Jul 22, 2006
NW Alabama
Is it necessary to remove the hydraulic lift cover on top of the axle housing in order to remove the gear type hydraulic pump? Any tips or tricks for removing and replacing the gear type pump on the 4000?
   / 4000 Hydraulic Pump #2  
No need to remove the lift cover. Remove the snap ring from the jumper tube connecting the pump cover to the flow control. Push the tube up into the flow control till the tube clears the pump cover. Remove the pump from the rear axle center section.
replace both jumper tube o-rings, clean the jumper tube and replace the pump cover gasket and suction tube o-ring when you reassemble.
   / 4000 Hydraulic Pump
  • Thread Starter
I wanted to update this post for people looking for the same info in the future. Everything went exactly as RickB stated except I did have to remove the top cover. When you pull the pump from the side of the tractor you can see the suction tube. Its about the size of a quarter. RickB mentioned this above. On my tractor there is a second smaller steel tube. This tractor is and 8 speed and has the independent PTO with the engagement lever on the opposite side of the tractor under the seat. I don't think all 4000's have the independent PTO? This small tube supplies hydraulic fluid to the the PTO engagement lever valve inside the tractor. This small tube was free to move horizontally. I tried to position it where I thought it needed to be and installed the pump. I started the tractor and the lift arms worked but the PTO would not engage. I pulled the top cover so I could see and of course the small tube was not in the port on the pump. I had to pull the pump and reinstall it with both tubes in their ports in the pump. It work great now.

Things I wish I would have know before removing the top cover: There is a small tube sticking up from the "deck" into the top cover near the front right corner (see first pic). It sticks up about one inch. You have the lift the top cover just enough to clear this tube and then pull the top cover to the rear about 3 to 4 inches. You cannot simply lift straight up due to a steel piece (see next two pics) (not sure what it does) sticking under the housing. From the pictures I have looked at not all tractors have this tube or the steel part that sticks under the housing.


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   / 4000 Hydraulic Pump #4  
The part that sticks out on picture 2 and 3 is a safety relief valve that all 3pt systems have. It protects the 3 pt when it gets overloaded or it has a heavy attachment and you go over a bump, it gives a little bit so other parts don't break.

It is usually set a bit higher that the system pressure.