Fixing an Across International 1.9 cuft Vacuum Oven for Deep Vacuum

So recently I’ve been working with a brand new Across International 1.9 Cubic Foot Vacuum Oven.

To measure a deep vacuum I use a Fieldpiece SVG-2 Digital Vacuum Gauge, it reads in microns of mercury.

Unfortunately I couldn’t get it to pull a vacuum that the digital gauge could read anything but OL (Over Limit).

I was using a 9 CFM Yellow Jacket SuperEvac Vacuum Pump and tried running it for 9 hours straight! No luck.

Then I opened the side panel of the unit and found this:
ai-before

From the internal shutoff valve there is a T-Junction to the Vacuum Outlet and a Gas Inlet on the back:

ai-back

 

From what I can tell there is only a little plastic cap between open air and my vacuum, no gaskets or anything..

So I  just removed the gas inlet connection, luckily the hose was just barely long enough:

ai-after

Problem solved! I can now pull a deep vacuum, no problems.