I am taking Scott's advice & having all my westy's bodily fluids
changed as routine preventative maintenance before a 500 mile rt trip
this weekend to the Henry Mtns in South Central Utah.  Flushing,
changing coolant, brake fluid, Tranny fluid to "Royal Purple"
synthetic, oil filter @ 3000 miles w/ Mobil 1 20-50W still good,
repacking front wheel bearings, & inspect for any leaks, etc.  I might
even rinse out the water tank w/ baking soda & install new waawaa.
Both batteries are sealed, so nothing to change there.

Am I missing anything?

YMMV,

Mr. BZ-uhoh, here comes another bodily fluid thread