i have a hand pump that makes pressure and vacuum, i cannot recall where i bought it from, but that is what i use at work when testing this sytem. usually if the pods are good, it goes pretty quick either way, so i would unlock all doors and pull vacuum with a hand pump, if they all lock , the pump is likely your culprit. i have a few extra pumps, if you are interested in trying out one, i will install it in my 500 and verify it is good,. and can send it in the mail