minecraft 1.15.2
the pump does not pump oil - mods PneumaticCraft: Repressurized https://www.curseforge.com/minecraft/mc-mods/pneumaticcraft-repressurized
whose fault is this ?

s?

The fluidic plenisher is for placing fluids the electric pump is for picking them up. Based on your picture I am guessing you are using the wrong machine.