vacuum pump

all right fellas since my truck was new i could hear the vacuum pump run. well now im at 250k and i stopped hearing it. i turned the key on and listened and its not running but all my functions still work. ac 4wd all that stuff. do you think its got enough pressure or is it just running off what was left in the tank? also what all does it control? they sell for 90 bucks at the parts house, should i pic one up or just wait and see what happens

Wait on it.

Get out and with the engine running, disconnect the line running from the pump to the reservoir. Bet it comes on. To prove it, stick your finger over the end of the hose. Make sure your A/C is on, that will demand vacuum.

I know mine works but its quiet unit