I want to brush the pile up on my carpet.

Question

I want to brush the pile up on my carpet do I need a special attachment to do this??. I have shampood it and it still seems a bit flat. When I shampood no water/foam filled up in the front tray???
I am sure I had attached everything correctly. The only thing I can think of is when I attach the brush and tray to the front of the machine, do I turn the handle back to the right way up, or do I leave it upside down, this is the one that picks up the belt.