ProMaxx Tool’s new Cylinder Head Repair Kit allows technicians to rescue a botched repair where an attempt to drill out a broken exhaust manifold bolt has penetrated the cylinder head. After fully extracting the damaged bolt, a technician uses a machine-shop-grade tooling tap to prepare the hole. Then, the included new Blind ProSert, with a light coat of liquid thread lock, is inserted into the hole, completing a repair that will remain leak free. The Blind ProSert fits into any 8-mm bolt hole, used by most automotive manufacturers. The Blind ProSerts have hardened steel and black-oxide-coated for corrosion resistance. They are available individually or in packs of three and six.