D15 I Hydraulic Pump Rebuild

I'm about to take the pump out of my D15 Series I. It is an early serial (1324 if I remember right).

What should I keep an eye out for? Is taking it apart and cleaning enough?

The book says add or remove shims to adjust pressure. What direction does what? What's the starting place for shims?

I'm pretty sure the relief AND unloading valves will at least need shims adjusted. My pressure barely tips over 2,000 now, and hovers around 1500 when running. Won't even lift the grader blade anymore.

I do not believe the hold position,control, or really anything else will need to be changed.

The book recommends a couple spring changes I will be doing.

AGCO will have the parts that I need?

I'm pretty sure that there are some linkage connections that have to be removed.  Also check the pump camshaft, make sure that the cam rotates when the clutch is out, and that all the lobes are there and smooth. We are talking about the pump that is inside the hyd compartment, right?  No metal in the pan?

You have to use a big flat blade screwdriver to compress the coil spring and shove a small nail in the hole on the rod to keep the spring compressed. Then, the pump can fall out.

You've got the nail on the wrong side of the bracket the rod slides thru.

Still not coming. Do I need to disconnect the outlet pipe from on top of the torque tube? How does the pump get fluid into the hose?

Must be hung up on the alignment dowels. Don't mess with the discharge tube. Somehow need to pry it down out of there. Don't let it land on your face.

DrAllis wrote: Must be hung up on the alignment dowels. Don't mess with the discharge tube. Somehow need to pry it down out of there. Don't let it land on your face.

It almost did when it finally came. When the book says "lower it out" they mean, "put all your body weight into it"

Does anybody know the dimensions of the Shim for the overload valve spring? My local AGCO dealer can't get it, and I feel like I should be able to just use a washer/spacer on lieu. Just need to know the thickness range to shoot for.

As per the service manual "each shim raises pressure 125 psi" whatever thickness each shim actually is.  ***** A tired pump that needs Orings, balls and springs will have the pressure increased quite a bit without adding any shims. So, don't think you need to add 10 shims to get to 3,000+ relief pressure. In fact, the service manual says no more than 6 springs total, which I never adhered to.

Edited by DrAllis - 15 hours 3 minutes ago at 8:36pm

And I cannot tell you how thick an OEM shim is if you don't have any to measure.

DrAllis wrote: And I cannot tell you how thick an OEM shim is if you don't have any to measure.

Tell me if this sounds stupid.

An SAE 3/8" washer has an OD of .8125"+/- and thickness 0.065"+/-, I'll have to measure the guide rod, but it should fit in a 3/8" washer.

Use a grade 8 SAE 3/8" washer as a shim? Take a file to any dangly/sharp bits so there's no potential fragments to dislodge in the pump.