Brake booster vacume pump.

Vacume is about 19 when driving,12 at idle in neutral, in gear stopped about 4-5 thats why Im thinking a extra pump. I drove it about 50 miles today and it works fine on the road and at stop signs, just a little iffy in the drive way turning it around and stuff when you hit the brakes 3-4 times it uses all the vacume.