Vacuum cleaner? Why not do as I do and blow it with your mouth?
The test needs very little pressure and if there are no leaks it takes just a few blows to get the required pressure in the tank. You will need to keep the measurement part closed with your thumb while blowing to prevent the water from escaping. Then put your tongue in the blowing tube and release your thumb to see if sufficient pressure has been build. Once the water reaches the upper and lower lines double fold the blow tube of the device and hold it firm and start timing.
My board has five lines, the zero pressure line, the start pressure lines (top and bottom) and two end pressure lines (top en bottom) I blow the tank until the water crosses the upper line (give it some time to settle). The timing starts when it crosses the top and bottom lines. It should then not cross the next set of lines within the measurement period.
It is actually a pretty simple process (but hard to describe as I just found out 👿 ). I intend to take some pictures when the season starts and we all need to check our boot anyway. I think a picture is worth a thousand word in this case. I shall put the result on the WIT site.