Download 2006-2011 GM 3.6L VIN D & 7 Check Valve Removal Process To remove the check valves, follow the procedure listed below. The use of GM special tool #EN 46122, a camshaft position actuator check-ball valve remover/installer, is suggested to assist in procedures. 1.Place cylinder head on a firm surface with check valves (1) facing up. Protect all cylinder head components and machined surfaces. 2.Using drill bit EN 46122-3, drill out top portion of check valve to expose internal check ball. 3.Remove check ball (1) and check ball spring (2) from inside of check valve. Continue drilling remainder of check valve sleeve to a depth of approximately 19 mm (0.75”) (a) by placing tape on drill bit as a depth gauge. It is not necessary or desirable to drill completely through the bottom of the check valve. 4.Lubricate tap EN 46122-4 with lubricant included in EN 46122 – remover/installer. Tap drilled out portion of check valve (1) remaining in cylinder head. Tap to full depth possible until tap bottoms out in head. 5.Assemble bolt, nut, washers, and collar EN 46122-2 (1) as shown. Position the collar with slightly-larger inside diameter DOWN toward the cylinder head. 6.Screw bolt by hand fully down into threaded check valve sleeve, then lightly tighten the nut against washer. 7.Hold bolt with one wrench, and use another to tighten the nut until the check valve sleeve (1) is removed from the cylinder head. 8.Clean check valve bore and related passages thoroughly to remove any drilling chips and/or other debris.