Truck has been parked for a little over two years. I changed the oil and antifreeze a few months before storage. I started it every few months to get everything "wet" and maintain battery charge. It started up great when I took it home last week!

Should I be concerned about any of the fluids sitting for so long? (Oil sits in the bottle for years, right?)

I know the "best thing" to do is change ALL fluids, but the truck will get very intermittant use (maybe one short trip a week) and I don't think I can justify the cost of total fluid replacement.

I had to top up the brake fluid (MC did not go dry) so there is likely a small leak somewhere I will need to track down, and the only other problem is my washer pump does not seem to be working (press the button and no sound of motor) Probably rusted and needs replacement. . .

Definately change the enigne oil! the additives break down after a year...
as for diff and t-case and tranny... i'd change them if i were you...

Brake fluid is hydroscopic.. meaning it will absorb moisture.. Moisture causes corrosion especially wheel cylinders, which in turn causes seal failures and leaks..

Since I've been flushing new brake fluid through the system every 2 years, have not had any brake component or seal failure..

Before that, used to have them every so often.

x2 on the brake fluid. Includes clutch system too, if applicable.