if you purchased a used tacoma with lets say180k mi and you have no clue what maintenance has been done to it, what would you change/replace/check for first and foremost?
ya im trying to run thru it but ive done most of those minus the diff fluidMe? First, I'd change every fluid. Engine oil, transmission, coolant, and diff. Inspect brake fluid. A new OEM thermostat is something to consider when flushing the coolant. The reason I'd change regardless is the way the maintenance schedule is design by Toyota. If you change your oil, coolant, etc. on schedule the fluid you take out is still good. You don't wait for them to go bad before changing, otherwise your doing damage.
I'd pull the sparkplugs. If they are ND or NGK and in great shape I'd leave them. A different brand or signs of wear I'd replace. If the cap and wire set were not Denso I'd get rid of those, too. but that's me. Make your own call on that.
Pull the wheels and check brake percentage, along with checking for any oil leaks. Especially at the shoes.
Check air filter, replace if needed. Same with wiper blades.