A modified filter screen for use in a downhole drilling operation is disclosed. The filter screen is able to be installed at the surface of a well, and is pin-loaded for easy access and maintenance. The modified filter screen may be retained within a section of pipe below the top drive above the rig floor by allowing dowel pins on the section of pipe to engage with latch slots on the filter screen. The modified filter screen may also be retained by engaging a threaded connector on the filter screen with a threaded connector on the interior of the section of pipe or by utilizing pins and/or retaining rings.