Adding Power Beyond, 3-spool hydraulic valve, and T-n-T to a JD 2520

[jimgerken]

I will use this thread to document all the hydraulic additions to my 2520. I will append as I get stuff done enough to show it. I wish to show enough detail so someone could follow along if desired. I will show all the plumbing, and provide the fitting types where it would be helpful, especially when interfacing to the tractor existing hydraulics (DSCV loader valve and three-point lift). I do not intend to use the John Deere Power Beyond kit if I can avoid it. At this point I am assuming the system will be identical to the JD 4100 hydraulics, to which I added similar options in 2001 or 2002. This system will have three additional spools, with couplers available to the back of the tractor, but one of the spool circuits will "T" and hose-route to the side of the tractor where the existing loader couplings are made. Later I will add a set of hoses and coupler nipples to route this circuit along the loader frame to the front crossbar where it can have mounted couplers to allow use with a grapple. And of course, Top and Tilt cylinders will be chosen, mounted and plumbed for the 3-point.

The first part of this process is to mount everything so the plumbing can then be planned and performed.

Starting now with the 3-spool Prince sectional valve mounting. I wanted it mounted on the right side, behind the seat, up 2.5 inches, at a 7 degree angle (so the back is lower than the front for ergonomic reasons and so maybe the inevitable spilled oil drops will run off the back and fall to the ground instead of running down the tractor fender and 3-point area). When you order a Prince sectional valve, you configure whatever you want. I chose the basic three spools for double acting cylinders, no float or regen, spring return to center, open center, and no power beyond (PB could be added later). In addition to the three working sections, there is an input and an output section. Overall the thing is about 8.5 inches wide, so it's kind of big for this small tractor, but it fits. Of course, the normal lever position on these is "lever straight up" on the front of the valve. Once mounted in the place there is room for it on my tractor, to operate it I would have to turn halfway around and still it would be a tough contorsion. So I designed and built a "forward control" set for it. This takes the standard levers and positions them out in front of the valve, laying forward at about a 30 degree up from horizontal (position and angle chosen to allow the important drink-holder to stay accessible and the 3-point position control still works fine). I chose to extend the length of the Forward Control set by about 4 inches, to put the lever handles right under my hand when seated and facing forward. Time for a few pics, and more to come of course...

 

[jimgerken]

After the valve mounting was complete, I started on the sidelink. I chose a cylinder from Surplus Center, their part number 9-6467-04. This is the largest cylinder that could fit in the space. The length is max, at 8.5 inches for the bare body alone after cutting the fittings off. The diameter is actually a bit too big, so the top fitting is installed offset to the "back" as much as possible. This works well in practice. I put it in the hacksaw and cut the bottom fitting off, and then cut off the rod end fitting along with about 3/4 inch of the rod itself. The fittings get welded on at an angle, and this is an important one, then drilled properly. The mid-stroke length is to be 16.5 inches to match the fixed-side length. that gives two inches up, and 2 down, which should be plenty. I think 1.5 each way is enough actually, if you find a 3 inch stroke cylinder that fits better (but I could not find it). BTW, this is a rebuildable cylinder, not welded shut which could be shorter overall, in case you need that. These pics show the fittings tacked in place. Final welding will be done today. For welding, first I grind off the chrome area so as not to include it in the weld. Then the goal is to keep the rod as cool as possible and protected from splatter by wrapping it with a wet towel and cooling it down after each weld, with a bucket of water. It would be better yet to dissassemble the cylinder but I am too impatient for that. I have done this procedure five times now with no apparent damage to the seals or piston, so it must be working. For welding the bottom end, first I extend the rod as far as possible to get the piston farther from the heat. Again I protect the rod and cool often. Try to keep the fluid ports out of the water. Pics...

 

[jimgerken]

With the sidelink almost done mechanically, I put on the purchased top link. I had chosen Agri-supply part number 67464. This one fits my tractor perfectly, and is reasonably priced. The ports on this cylinder and the sidelink cylinder are all SAE 8. This is the type that uses an "O" ring and a jamb nut with washer to put pressure on the "O" ring. So if using a 90 degree fitting, it can be angled any desired direction and then the jamb nut tightened to hold the position and make the seal. This method sure beats tapered pipe where you know for sure it will tighten in the wrong position. Pic...

 

[glmf]

nice job Jim, appreciate the detail in your posts and the photos. Thanks for taking the time to post and please keep them coming

 

[kennyd]

Good work Jim

 

[crbr]

Well Jim, I gotta' say, I envy your shop skills to make this work to your suitability. Nice job indeed.

It should be a federal law that if you post pics of something this customized and functional, you should have to fix mine like this too....

 

[Nickahawk]

That's as "clean" as it gets. I envy your skills!
Nick.

 

[mwood]

I love all the details! One of these days I'm going to actually take that welding class at the local Community College. But before I spring for a welder, I think I need to spring for the tractor!

 

[jimgerken]

Everything got painted Saturday morning.

 

[jimgerken]

Even though my huge order of fittings and hoses has not arrived from Surplus Center yet, I was anxious to get started so I tore into it last night. Jacked it up, placed jackstand under, removed right rear tire...

 

[jimgerken]

The stock DSCV is visible here. Behind it, sandwiched between the DSCV and the transaxle is the "block" which allows tapping into the hydraulic flow. It is easiest if you get the block out of the tractor for the simple mods that must be done to it. To remove the block, two M8x50 hex socket head cap screws need to be removed. Unfortunately one of the loader hard line fitting banjo bolts is obstructing access to the lower cap screw. I remove the banjo bolt, and then remove the two cap screws ( I am pointing at them in this photo).

 

[jimgerken]

OK, then slide the block out while pulling gently on the DSCV to gain clearance. Take the block out the back of the tractor direction. It's an oily mess, but luckily no real quantity of oil comes out of the now-open transmission. Here's the block.

 

[jimgerken]

This next pic shows the block in my hand, upside down. The two open ports visible are normally facing down. I have uncapped them. They are the Supply and Return lines attaching points. Threads and fitting type will be verified today and data posted soon.

 

[jimgerken]

A set screw, John Deere part number PT13744, must be threaded into the block, inside the "front facing" port.

 

[jimgerken]

Here's the setscrew being tightened inside. You can actually see it thread past the port. After this, the port plug is reinstalled. And then you are ready for fittings, which I have not received yet. Will show them in a day or so. Over and out........

 

[jimgerken]

Before I forget to do it, the torque specs I found and use are:
Banjo bolt 150 inch pounds (8 mm hex wrench).
M8x50 cap screw holding DSCV on, 17-22 foot pounds (22 mm socket).

 

[3RRL]

Great mod to the tractor. An improvement making it 10x easier to use and manipulate your implements and also hook ups. Super sano job too, I might add. It really looks great so far. Just wait 'till you start using the top 'n tilt. You won't believe how you ever got a long without it.

 

[jimgerken]

!!! Could it REALLY take all this stuff to get the job done ??? Actually, some of it is in a drawer yet, not in the picture.

 

[jimgerken]

So, fittings aplenty, I tackle the "block". First problem, I can't rotate one fitting if the other is installed. After studying it for a while, I decide that it is not worth another trip to the hyd store, so I ground off the one fitting just a bit, grinding just past the lead-in chamfer, halfway around. Now it swings just fine. So I proceed.

 

[jimgerken]

So here is both the fittings and a 45 degree fitting with swivel attached. Note, the thread in the "block" is SAE 6. The SAE fitting allows you to position the direction wherever you wish before tightening the jamb nut.

And the hoses get assembled. In my case, 36 inch hoses worked out well. 33 inches would have been ok too. My hoses are 1/4" NPT male, so I convert to that on both ends with fittings.