iRobot Scooba 380 / 390 "check tank" possible fix

Sometime you start the scooba and it faults after 2-3 seconds with the "check tank" fault. One possible fix is to inject liquid into the Scooba cleaning system before starting. I use a bike pump with some rubber tubing. The tubing must fit over the small valve (has a visible spring). It is located to the right of the battery and above the button to release the brushes.
Step 1: remove battery
Step 2: fill tubing with small amount of water by using bike pump to suck it in
Step 3: insert tubing over valve
Step 4: Slowly pump water in using bike pump. You should see water some out of the 2 jets underneath.
Apologies for quality of video. My 10 year old is learning !