WARNING  Coolant is toxic.  Keep away from children and pets. If not reused, dispose of in accordance with local environmental regulations.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Disconnect the batteries. Refer to the OEM service manual.
• Drain the cooling system. Refer to Procedure 008-018 in Section 8.
• Remove and disassemble the cylinder head. Refer to Procedure 002-004 in Section 2.

Use slide hammer assembly, Part Number 3376617, and valve seat extractor, Part Number ST-1279-1, to remove the valve seat inserts from the cylinder head.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Use a wire brush and solvent to clean the deposits from the valve seat insert bores.

Use solvent to clean the cylinder head.

Dry with compressed air.

Inspect the insert bore for cracks or other damage.

NOTE: If cracks or other damage is found, it is possible to repair the cylinder head by machining the insert bore for oversize valve seat inserts. Refer to the Alternative Repair Manual, Bulletin 3379035.

Measure the valve seat insert bore depth in the cylinder head.

Insert Bore Depth (Standard Insert)

NOTE: If the valve seat insert bore depth does not meet the specifications given, it is possible to repair the cylinder head by machining the insert bore for oversize valve seat inserts. Refer to the Alternative Repair Manual, Bulletin 3379035.

Measure the inside diameter of the valve seat insert bore in the cylinder head.

Insert Bore Inside Diameter (Standard Insert)

NOTE: If the valve seat insert bore inside diameter does not meet the specifications given, it is possible to repair the cylinder head by machining the insert bore for oversize valve seat inserts. Refer to the Alternative Repair Manual, Bulletin 3379035.

Install the base and swivel of the valve seat insert tool, Part Number ST-257, on the cylinder head to guide the valve seat driver.

NOTE: The insert chamfer (1) must be installed toward the bottom of the counterbore.

Use the valve seat driver and an arbor press to push the valve seat insert into the counterbore.

NOTE: Make sure the insert is at the bottom of the counterbore.

Use valve seat grinding machine, Part Number ST-685, and valve guide arbor set, Part Number ST-663, to grind the new valve seat inserts. Refer to Procedure 002-004 in Section 2.

WARNING  Coolant is toxic.  Keep away from children and pets. If not reused, dispose of in accordance with local environmental regulations.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

• Assemble and install the cylinder head. Refer to Procedure 002-004 in Section 2.
• Fill the cooling system. Refer to Procedure 008-018 in Section 8.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine and check for leaks.