Ford 4630 Flow Control Valve leak

Hi All, as mentioned in my last post I recently got my hands on my FIL's old Ford 4630. I am working on tracking all of the major leaks down to get the tractor ready to use on my property. Right now I am focusing on the Flow Control tube between the Flow Control and the pump. Looking at some exploded diagrams I can see the tube and an o-ring in the pump for the tube but when I run the tractor and the FEL I see the fluid is actually running down the tube from the Flow Control and not up from the pump, you can kind of see this in the pic where the entire tube is covered in oil and not just the base. This leads me to believe that the issue is not with the o-ring in the pump but is something else in the flow control valve. In my other post Destroked 450 pointed out that I am missing the Snap Ring on the tube. Is it possible that the lack of snap ring has allowed the tube to creep down preventing proper seal in the valve allowing fluid to flow from the valve?

If the issue is with the tube, snap ring and o-ring is there anything I need to know about replacing the tube? Does the Flow Control valve have to be removed or is there play in the tube to lift and replace the o-ring? This will help me in knowing what I need to purchase in addition to just an o-ring (i.e. Gaskets, other O-rings affected by the removal)

I just downloaded the Service manual and it indicates that to remove the Flow Control Valve the Lift Cover must be removed. So it looks like I will need a gasket and some extra O-Rings to take this one on. The manual mentions a installing a lifting bracket once the seat is removed. Any idea which bracket one would use for this? Is it even necessary? I research says this cover is well over 100lbs so I lean towards having it to reduce the risk of my really DIYing it up.

The cover can be lifted by hand - I've done it when I was young and dumb, but I wouldn't today, I'd hurt my back for sure. The lifting
bracket is simple to make. All you need is a flat plate with two holes to bolt over the seat mounting bolts. Weld a loop in the middle and
you've got a lifting bracket.

The tube between pump and flow control valve pushes up into control valve body. The wire ring goes in groove at top of tube.

(quoted from post at 15:34:10 06/29/20) The tube between pump and flow control valve pushes up into control valve body. The wire ring goes in groove at top of tube.

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Thanks Shaun, I have been looking over the Service manual and found the note about being able to pus it upwards to clear the pump.

(quoted from post at 15:34:10 06/29/20) The tube between pump and flow control valve pushes up into control valve body. The wire ring goes in groove at top of tube.

Click to expand...

In your opinion, with the oil seeming to come from the Flow Control Valve and flow down the pipe would the failure likely be in the O Ring on the flow tube or do you feel it will be the O Rings under the Lift plate?

I was able to get a small screwdriver and found the C Clip and was able to move the pipe around. I will start with that O-Ring first and see if that resolves the issue. If not I will go for the upper seals in the valve body.

Yes oring and backup on both ends of tube. It mite be eaiser to pull pump. Yes step will have to come off and drain oil.

Great, thanks. I am going to try to make it to the NH dealer tomorrow and pick up the parts.

I wish this forum had a like or thumbs up option so I could acknowledge comments without having to reply.

(quoted from post at 18:27:21 06/29/20) Yes oring and backup on both ends of tube. It mite be eaiser to pull pump. Yes step will have to come off and drain oil.

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Yeah, if I have to drain it I will do the PTO seal at the same time since it is also leaking.

to replace those o-rings. remove the clip that is on the tube, slide the tube up replace the lower o-ring, then slide the tube down replace the upper oring. not really a
big deal

(quoted from post at 07:58:18 07/01/20) to replace those o-rings. remove the clip that is on the tube, slide the tube up replace the lower o-ring, then slide the tube down replace the upper oring. not really a
big deal

Click to expand...

Great, I am going to go out today and verify the tube slides as described. This will make the repair much easier if there is room to slide it up and down to replace the rings.

(quoted from post at 07:58:18 07/01/20) to replace those o-rings. remove the clip that is on the tube, slide the tube up replace the lower o-ring, then slide the tube down replace the upper oring. not really a
big deal

Click to expand...

I just went out and I got the Snap Ring off of the tube but when I try to slide the tube up I only get it to move about 1/8" then it stops. Any tricks for moving this without damaging the tube?

Looking through the service manual the only reference I see to this pipe is when removing the Hydraulic pump

"Note: The externally located feed pipe, connecting the pump to the flow control valve plate, must be pushed upwards a sufficient distance to facilitate removal if the pump."

There is no info on how to move the pipe. I have tried to use a screwdriver to pry it upwards but I can only get so far, fairly easily at that, but then it seemed to hit a wall and wont budge. Now when I try to move it I scar the pipe. I worry that I will end up damaging it to the point that I ruin the mating surfaces and make the leak worse.

Well I went digging in the old toolbox junk drawer and found a thin 14mm throw away wrench that came with some tool or piece of furniture that fit the the grove on the pipe perfectly. I was able to build up the base and slowly move it up and expose the o-ring. Hopefully I will be able to move it down the same way. I am not sure if the Grove where the scring clip was is the same size to be able to push it down into the pump once these are replaced. I may just remove the bottom rings and then replace the top and slide it back up to replace the bottom, that way it will slide easier.

Well that little trick was great for lifting the pipe up into the flow control bit not so much getting it back down
It has stopped moving again at the O-ring and I broke my little wrench while prying in it.