Thumper ran nearly dry?

[tom sawyer]

Just got my thumper for my Brewhaus 7gal still. I'm using the bottom half of the 30" column then to the stainless thumper. Maiden voyage was brandy and I put wash in the thumper to a little less than half full. Had a good run and I feel like this is going to make a more flavorful product than stripping and spirit runs.

When I took the thumper apart after the run, there was only maybe 1/2" of liquid in the bottom. Is this normal? Should I be charging it with more liquid? Getting ready to start another run today, more pear cider wash.