For 1990-2009 cars

# DIESEL HEAD GASKET LEAKAGE SUMMARY INFORMATION

#### Models Affected: All Diesel Equipped Vehicles

There are a number of items that must be considered when replacing a head gasket. The following checklist may help to make sure that you don't forget anything.

- Latest head bolts have "-" on top of bolt along with vendor code.

- Wire brush head bolts to clean threads.

- Oil threads of bolts and underneath head.

- Dowel pins hold head off block.

- Dowel pins off location.

- No dowel pins.

- Cylinder heads warped more than .010 inches.

- Prechamber +/- .004 inches from head.

- No damage in sealing ring area.

- No stamps in seal area around water passage.

- Water passage seal surrounds all water passages.

- No chips in bolt holes

- Bolt holes in cylinder block drilled and tapped deep enough.

- Follow torque sequence and installation torque procedure.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.