You might be able to rent one at your local parts store. I rented a vacuum tester at Oreilly's for 6 bux, and it worked good for testing my lower unit.
I tore the valve stem off an old bike tube and grund the rubber end to a sligt taper that will screw in the plug hole quite well. Then use the bike pump with the guage on it. Worked pretty well.<br /><br />But if ya want the real stuff try http://www.stevensinstrument.com/
