Method and apparatus for repairing a cylinder head

In a fluid-cooled internal combustion engine of the type having a combustion chamber and a cylinder head defining a portion of the combustion chamber wherein the cylinder head includes a cooling fluid passageway, a fuel injector bore and a boundary wall between the fuel injector bore and the cooling fluid passageway, a method of repairing a damaged portion of the boundary wall between the fuel injector bore and the cooling fluid passageway, the method comprising:

• disconnecting a fuel injector retaining clamp from a fuel injector;
• removing the fuel injector from the fuel injector bore;
• providing a sealant injector tool, the sealant injector tool comprising a generally cylindrical body having a lower portion adapted to conform to the dimensions of the fuel injector bore, the sealant injector tool having an internal passage with an outlet aperture, the outlet aperture being located along a lateral wall of the lower portion of the body, the sealant injector tool further comprising a seal-receiving recess formed around the outlet aperture;
• installing a resilient seal into the seal-receiving recess;
• providing a sealant within the internal passage;
• inserting the sealant injector tool into the fuel injector bore with the sealant injector tool oriented so that the resilient seal forms a pressure-tight seal between the outlet aperture and the damaged portion of the boundary wall;
• applying pressure to the sealant until it exits via the exit port;
• flowing the sealant under pressure from the exit port into the damaged portion of the boundary wall, the sealant flowing into the damaged portion of the boundary wall from the fuel injector bore side of the boundary wall toward the coolant passage side of the boundary wall;
• and
• removing the sealant injector tool from the fuel injector bore.