Anyone know anything about tractors?

I have an old John Deere 2240. Bought it several months ago, and it had some moisture in the hydraulic fluid and the brakes weren't working. I flushed out all the oil and had the brake valves rebuilt because the check valve inside was damaged. Now only one side works. The other side seems to be jammed up inside and there is no brakes on that side at all. The pedal will bleed all the way down when bleeding the brakes, so the valve is fine. Anyone ever took one of these apart to mess with the brakes. I'd rather do it myself, but I'd like to have the correct parts on hand so it doesn't sit around disassembled for a couple weeks. Anyone know what parts I should have on hand for this? TIA