secondary regulator

Hi, all. I know that this topic has been covered numerous times in general and that a lot of people have purchased these now-discontinued kegerators over the years, but I can't find anyone that has done this modification specifically with the Summit SBC-500B Kegerator. I bought this used this...

I bought a used keezer a couple of weeks ago. I cleaned everything, and swapped out a four way manifold for a brand new four body Taprite secondary regulator with check valves (mounted inside the keezer). I am trying to figure out if I have a leak. The keezer is located in my detached garage...