Welcome, in this video we will guide you through the replacement of o-rings in an O-Pro® Cartridge seal for pumps with the U-Plus™ bracket. This video applies to these pump models… Before you begin, please consult the appropriate technical service manual for safety information. A copy of the latest revision can be found on our website at vikingpump.com. To begin, bend up the tang of the lock washer. Place a brass or hardwood bar into the port opening to keep the pump from turning. Loosen and remove the locknut. Remove and discard the lock washer. Loosen the bearing housing set screws.