Step 4 · Remove and Identify the Old Cartridge

This is the step most people slow down on. Take it one move at a time — there’s no rush, and you can rewind the clip as many times as you need.

Grip the stem of the cartridge with pliers and pull it straight out of the valve body. It may be stuck from mineral buildup; if so, wiggle it gently from side to side while pulling. If it won't budge, use a dedicated cartridge puller tool to remove it without damaging the valve. Once removed, identify the cartridge type. The older Delta Monitor 1300/1400 series cartridge (model RP19804) is typically gray with a solid, round body. The newer MultiChoice Universal Valve cartridge (model RP46074) is typically white and has a more complex, squared-off shape. Note the orientation of the cartridge and the location of the 'H' marking on the valve body (usually on the left) for correct installation of the new part. Take the old cartridge to a hardware store to find an exact match.