9n Hydraulic problems

[Chris Klein]

I have a 41 9n with hydraulic issues. Everything was working fine and suddenly the lift would drop as soon as the clutch was pushed in, it will barely lift the front of the baler off the ground. I also noticed that with no weight on it when the lift was all the way up it seemed to bounce. The fluid obviously had water in it so I drained it and have had the lift cover, lift cylinder and pump apart to inspect them. I cant find anything bad but I still have no lifting power. Any ideas would be appreciated.
Thanks
Chris
 

[Dunk...]

Have you taken the right side inspection plate off and ran it to see where the fluid is leaking from?

That should have been "step 1".
 

[ZANE]

The 9N-TO Ferguson 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. I can fix that for you if you will Email me at wzsherman@aol.com or see the link

http://hometown.aol.com/wzsherman/myhomepage/sale.html

First thing is to be sure that the PTO is engaged!

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. Feel down to the bottom of the control rods and see if the control valve “T” shaped valve connection is firmly connected at both ends to the control rods. The rods have to be spread open to reconnect them if they have come loose from the control valve “T”. It is a lot easier to do this if you have both of the inspection plates off the lift housing so you can reach in from both sides.

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.
If you should decide to replace the piston rings and you find that the cylinder is scored badly, you should hone the cylinder and instead of replacing the steel piston rings and the original piston you might want to consider replacing the piston and rings with the Ford model NAA piston and the Neoprene Rubber rings. The NAA piston and rings is the same size and the rubber rings will seal much better than the steel rings.

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 it,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.

A couple of other things you can try to check out is first the pressure tube that is pressed into the housing and goes from the boss just above the pump to the boss just below the lift cover housing. These can rust enough to spring a leak. Sometimes hard to find???? One way you might try to look for a leak in the tube and or a blown gasket at the pumps base is to remove the lift cover. Push the control valve into the pump to the lift position and then apply air pressure to the opening on the top end of the pressure tube to see if it bubbles around the tube down under the oil. Either place will bubble if in fact the pump gasket is blown inside or the tube has a hole in it. If there are no bubbles there then you might be able to see the bubbles somewhere else to give you a clue as to what to look for.

The control valve has to be in the in/up position for this test to work. Otherwise the air will just come out the control valve.

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.
Also be sure that the control linkage is attached at the “T” at the control valve connection.
Zane in Alabama.

If you should be having trouble with the lift not going down when the lever is moved to the down position I would suggest that while the inspection plate is off on the side of the lift housing you reach in and manually push the two levers that go into the oil in the reservoir and are connected to the control valve. The control valve sometimes sticks in the up position. The control valve can also stick half way and cause the lift to weakly move up and be able to push the lift arms down or not lift at all etc. If you should find that you can make it go down by pushing the control valve arms toward the front of the tractor internally on the control rods then you should drain the all three places and pour about 5 gallons of clean kerosene through the lift with the drain open. It is best to pour it directly into the inspection hole. Let the kerosene that drains out sit for about 15 minutes and pour it through again leaving the portion that is in the bottom of the container to be discarded. This should have the residue in it that may have been causing the control valve to stick when it was carried into the control valve. This happens lot and water in the oil can cause sticking control valve especially in freezing weather.


ANOTHER THING TO LOOK AT IS THE LIFT WILL NOT RAISE AT ALL IS THE DRAFT PLUNGER AND ANCHOR PLATE WHICH HOLDS THE BIG DRAFT SPRING ON BACK OF THE LIFT HOUSING.

If this is a 9N/2N and has only draft control I suspect that the draft spring anchor plate that is part of the plunger guide assembly has been bent or warped outwards.

If this is the case you may have to remove the yoke from the end of the draft plunger link in order to remove the three 7/16" bolts that retain the anchor plate to the lift housing on the back of the tractor.

This "yoke" is usually going to resist removing because it is a fine thread of close tolerance and over time trys to glue itself to the plunger and will usually have to be heated red hot with a torch to get it started moving to remove it.

Do not use excessive force to try to remove it or you will surely break something inside the lift and then you will have even more trouble than you presently have.

You can try moving the quadrant back by loosening the four retaining bolts that hold the quadrant to the lift housing and hammering it back along the quadrant's elongated mounting holes. This is what the elongated holes were designed to do but if it still will not lift your only option is to do what I said about the yoke on the draft plunger link.

Be sure to try the lift before you go to all the troube of reinstalling the spring and yoke etc. It will work just the same as if it were assembled as soon as the anchor plate is re-installed.

If it still won't begin to lift when the touch control is moved to it's full up position you can then use my old trick to attain enough forward positioning of the internal draft link by again removing the anchor plate that is held with the three bolts and then fashioning a shim from a 5/8" flat washer that you have made a notch in to accomidate the dowel pin in the anchor plate that keeps the draft plunger rod from turning when the yoke is turned when installing or removing. This dowel can be broken off if too much torque is put on trying to remove the yoke from the draft plunger.

EXHAUST CONTROL VALVE SPRING DAMAGED OR MISSING
There is a more rare condition that will really put a monkey wrench into the operation of the lift on the 9N/2N. This is when the retaining spring that is an integral part of the exhaust control valve breaks or becomes too weak to actuate the exhaust valve when it is moved by the control linkage. The spring is located on the exhaust valve itself and has to be intact in order to move the valve when the linkage is moved. It may be necessary to pull the pump in order to inspect and repair the exhaust control valve.

You should also inspect the spring that is connected between the front end of the ram cylinder of the lift to the knee portion of the control rods that go from the linkage at the top to the control valve in the bottom of the pump. This spring sometimes looses it tension from age and usage and must have enough tension on it to pull the control valve out when the lever is moved to the down position.


There is also the possibility that the exhaust port in the control valve bushing have become plugged with foreign material such as plastic shavings or gasket material etc. When this happens the only fix is to pull the pump out of the tractor and drive the bushing out and clean the ports of what ever junk is plugging the ports.

The pump is a four cylinder piston type pump. One or more of these four pumps can be disabled and the pump will still lift the same amount of weight or close to it but will tremble or jump on raising. Sometimes the valve chambers of the pumps may leak if the hold down bolt that plugs the valve chambers on either side of the pump come loose or the seals become eroded. Sometimes a broken valve spring or springs in the valve chambers can cause a skipping pump or intermittent pumping action causing the lift to pulsate on lifting. The problems with the pump can only be corrected by removing the pump and inspection of pump parts and replacing or repairing such parts.

Zane Sherman
Talladega Alabama
 

[James Shepherd]

Hey Zane and Chris. Hope you guys stay close to this forum. I am about to reinstall the hyd pump in my 8N. Really appreciated the tutorial on pumps from Zane. Chris hope yours turned out OK. My hydralics suddenly quit. Had some broken links under lift cover but no pressure after repalcing them. Sump was very sludgy (sp?). Cleaned up pump and all parts seemed to have only normal wear. The book said that the steel valve bodies for exhaust etc should be flush with the surface of the pump body face but I don't think they were that way when I disassembled it. Also the drive cam that meets the pto shaft appears to have a beveled side I am assuming that that is to make shaft incertion easier. Mine is facing the other way. Is it critical to have the cam with the beveled edge facing rearward? thks Gentlemen.