Mine has two chambers for soap or liquid wax or whatever, valve to switch between the two.
It lost pressure after the first year. Thought the pump was toast, but got online and found out there are several little cartridges within the pump that control the pressure.
Called the pump MFG and got the cartridges sent to me at $30 bucks or so.
Full pressure now. Honda engine.
What's the make and model? I'd love to have such a creature.