Fuel Tool, check valve rebuild kitIncl. two o rings; a solid brass valve & stainless spring. A leaking check valve inside the fuel tank of fuel injected models is a common issue; but easy to solve. This tool eliminates the need for a new check valve and lets you replace the lower o ring or do a complete rebuild. Note: Used with 908546 fuel pump check valve tool kit. Note: See 908542 (ea) or 908543 (5 pack) for additional o rings.