Kevin I kinda had the feeling your machine was mis-plumbed from the start when you described a valve input teed into a outlet. Anyway Ive never had a bad item from Surplus Center..I'd be very surprised that your valve difficulty was caused by anything they sold you. They do have a reasonable return policy if the item was indeed defective.

I understand you're not wanting to shoot the moon on the budget with this machine..for my money I'd skip the flow dividers and plumb it (#1)pump circuit for travel/propel(wheel motors) forw/rev-- and the other (#2)pump circuit for steer and loader,either with a priority valve(steer-priority valve) and make the downstream valve the loader valve that way steering takes priority over the loader; or use one of the flow dividers you have..if you go priority valve then you have full flow and no reduction or division of flow GPM,your loader will be faster that way. My articulated loader works great with a priority valve as the steer valve,no issues for over 10yrs other than a blown up pump,but that was a used pump that was over 20yrs old. Do you have any ideas what your relief valve pressures are set at? Typically a valve right out of the box will be at 2000psi give or take...did you do any adjustment to the new valve?