There is usually no reason to rebuild the pump. It is the most trouble free component of the hydraulic lift on the TO Ferguson.
The trouble is more than likely with some other component. The Ford N tracotrs have the same lift and I will give you my trouble shoot for them.The 9N lift has no position control.To maintain the lift at a given position the hand must constantly be on the control lever to continually re adjust. The most common places to leak on the lift is the piston rings and the pressure relief valve.
In order to determine where the lift is leaking you should remove the right hand inspection plate that holds the dip stick for the lift oil.If oil runs out when this cover is removed it has too much oil in it and letting it run out is ok. Start the tractor with a load on the lift arms such as a rotary cutter etc. raise the lift and observe inside the lift to see where the oil is leaking down.If the piston rings are leaking their will be a pretty good stream of oil coming out the end of the ram cylinder. If just a few drops this is ok. Observe the oil in the resorvoir and if you see the oil swirling around the relief valve is probably leaking.It is the gadget that is screwed into the back of the hydralic pump just under the pto shaft.It will be under the oil and feels something like a spark plug. If before starting the tractor you will put your hand into the oil and locate the relief valve you can reach in and put one finger over the end of the relief valve and determine if it is leaking after the tractor has again been started. DON'T MAKE THE MISTAKE OF PUTING A FINGER IN THE PUMP MECHANISM!!!! If however you don't see a signifacant leak from the top you can assume that the relief valve is leaking and simply replace it with a new one and thereby prvent the possible loss of a finger or two. I;ve never tried itm,but I�ve read that you can drain enough oil from the lift reservoir to uncover the relief valve and see if it is leaking instead of using the obviously dangerous finger feel thing I described.
There could also be a blown gasket somewhere in the upper portion of the lift but if so you will see a lot of oil coming down from the top and then it�s just a case of taking the cover off and finding the culprit.
Be sure to release the control rods from the control valve T on the pump before trying to remove the lift cover. To fail to do so will result in a broken lift control valve stem.
Zane in Alabama.
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