1300 02 084 0.25 mm Piston & Liner Shim for FH12

What does a piston and liner shim do?

This piston and liner shim is a critical component used to bring the liner protrusion in heavy-duty diesel engines into the exact target range. By providing a precise thickness, it ensures the cylinder head gasket carries a balanced clamping load, which is essential for preventing gas leaks and premature gasket failures under high combustion pressures.

Compatibility and dimensions

This specific shim is compatible with FH12 engines. It features an outside diameter of 158.90 mm and an inside diameter of 152.10 mm, with a thickness of 0.25 mm. For precise fitment, always verify the engine's required protrusion range against the service manual.

Installation and maintenance guidance

During installation, technicians must ensure that all surfaces are thoroughly cleaned of residue or corrosion to prevent inaccurate protrusion readings. It is vital to use a single shim of the correct grade rather than stacking multiple thin shims to maintain structural integrity under high heat and load.

Best practices for engine assembly

Always measure each cylinder separately during engine overhaul, as block wear can vary between cylinders. If the liner has been removed, ensure all sealing elements are renewed to prevent coolant leakage into the crankcase.