Do something to run the pump and follow the noise it makes. The reservoir should be part of the pump or very near it.
Check it with all cylinders closed up. That will put the fluid at it's highest level so you can check it. If you don't close all the cylinders first, set the fluid level to spec then when you close the cylinders then you'll have fluid everywhere.
Typically, when it's set to travel, slides in, etc, is when the cylinders are closed.
Now-2014 Sierra 346RETS 5er BUB
Then-2002 Keystone Springdale 286RLDS TT
Nights camped in 2014-28, 2015-127, 2016-10