Where did the fluid go?

Now that we know how the oil is pumped and directed in a hydraulic circuit lets take a look at where it is stored. The hydraulic reservoir is the storage place of the fluid in a hydraulic circuit. The storage capacity of the reservoir should be at least 2 to 3 times the need of the hydraulic circuit. 

The fluid level is always rising and falling in the reservoir when the circuit is in use. The reservoir serves also as a place to catch any contaminates that may have ended up in the fluid. Most reservoirs consist of a fluid gauge, a breathing cap, baffle plates, and drain, return, and suction lines. 

When filling the reservoir one wants to make sure not to fill it completely full, this space allows for foaming which helps get the air out of the oil. The baffle plates help with reducing the heat of the fluid. Depending on the load and the use of the hydraulic system the oil can get very hot. If the hydraulic circuit requires the system to be pressurized then there will be no breathing installed. The included cut out diagram of a reservoir shows where the different components are located in the reservoir.