There is no screen, per se, that I know of.
There is a replaceable hydraulic and a replaceable transmission filter, both are spin on. There is a ring magnet inside one of them (hydraulic I think) and for good measure I cleaned it with brake parts cleaner and masking tape and put in into the replacement filter which did not come with one. SOP at my place is to fill all replacement filters before installation.
All the best,
Martin