Kyle, You made a mistake buying that machine for the purpose of vacuuming AC systems... we have said that in many threads... but here is one from Aircondition.com to that effect also...

http://www.aircondition.com/tech/questions/38/Air-Powered-A%7B47%7DC-Vacuum-Pumps

If you did not want to buy a good vacuum ( I can understand that ) then you could have rented it from a local equipment rental for a weekend...

The old style vacuum pumps just had a hole which the water would drip out of..