Cylinder Head Gasket Selection
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
Special Tools
J 7872 Dial Indicator Set
For equivalent regional tools, refer to Special Tools
- If a reciprocating component (crankshaft, connecting rod, piston, or bearings) has not been replaced, install the same grade head gasket that was removed.
- The cylinder head gasket thickness is determined by the piston head projection from the cylinder block deck surface. There are cylinder head gaskets available in three different thicknesses. Follow the procedure below and refer to Cylinder Head Gasket Selection Specifications to determine what gasket to use for each bank of cylinders.
- Be sure the piston and cylinder deck are free of carbon, gasket material, or other objects that may give you an erroneous measurement.
Use J 7872 dial indicator set to measure the piston projection across two different points on each piston.
- Zero the dial indicator to the cylinder deck surface.
- Place the dial indicator pointer on the piston top. Be sure the pointer is directly above the piston pin centerline to prevent inaccurate readings from piston rocking.
- Rotate the engine to roll the piston through Top Dead Center while noting the maximum reading on the dial indicator.
- Repeat procedure at the second measuring point on the piston.
- Obtain the maximum piston projection value for that bank of cylinders.
- Determine the gasket grade by the maximum piston projection value using the chart. Refer to Cylinder Head Gasket Selection Specifications .