To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.
Never use the following to clean gasket surfaces:
NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.
Only use the following for cleaning gasket surfaces:
CAUTION: Excessive pressure or high RPM (beyond the recommended speed), can damage the sealing surfaces. The mild (white, 120 grit) bristle disc is recommended. If necessary, the medium (yellow, 80 grit) bristle disc may be used on cast iron surfaces with care.