SHEAR GP-HYDRAULIC 2405912 - Caterpillar

Replacing valve seat
Illustration 12 g02212584
Removing valve seat using valve seat puller (9) Weld (10) Valve seat (11) Shaft (12) Stud
To remove the valve seat, weld a stud to the valve seat as Illustrated. Then, insert a rod into the valve guide hole from the top of the cylinder head, and press out the valve seat with the rod.Be careful not to allow spatters to adhere to the machined surface of the cylinder head during welding.
Illustration 13 g02212585
Valve seat fitting bore
Before inserting a new valve seat, measure the cylinder head bore diameter to make sure that the interference meets the specified value.The following dimensions applicable for inlet (R) Dimension ... 8.800 0.100 mm (0.3460 0.0039 inch) (V) Dimension ... 41.0000 + 0.0200 - 0 mm (1.6100 + 0.0008 - 0 inch) (T) Dimension ... 2.800 0.100 mm (0.1102 0.0039 inch) (X) Angle ... 45 degreesThe following dimensions applicable for exhaust (S) Dimension ... 8.800 0.100 mm (0.3460 0.0039 inch) (W) Dimension ... 33.000 0.020 mm (1.3000 0.0008 inch) (U) Dimension ... 2.800 0.100 mm (0.1102 0.0039 inch) (Y) Angle ... 45 degrees
Illustration 14 g02212586
Driving in valve seat
Cool the valve seat for 4 minutes or more in liquid nitrogen (at approximately -170 °C (-274 °F)) before fitting the valve seat into the cylinder head, while keeping the cylinder head at room temperature. Or heat the cylinder head to 80 to 100 °C (176 to 212 °F). Cool the valve seat sufficiently in ether or alcohol mixed with dry ice before fitting the valve seat into the hot cylinder head.
Fit the cold valve seat into the cylinder head using the insert caulking tool (13) (Inlet P/N:30691-02700, Exhaust P/N:30691-02800).Refacing valve face
Illustration 15 g02212587
If the valve face is drastically worn out, reface the valve face using a valve refacer (14) .Note: Grind the valve face using the valve refacer at the specified angle (15). Secure the valve margin width equal to or greater than the limit. If the dimensions after refacing does not meet the specified values, replace the valve with a new one.Refacing valve seat
Illustration 16 g02212589
Use the valve seat cutter or valve seat grinder to reface the valve seat. After refacing, sand the valve seat lightly using 400 grit sandpaper, insert the sandpaper between the cutter and valve seat.
Lap the valve in the valve seat.Note: Valve seat refacing should be kept to an absolute minimum. If the valve seat width exceeds the limit due to wear or refacing, replace the valve seat with a new one. If the valve sinkage exceeds the limit after refacing, replace the valve seat with a new one.Lapping valve and valve seat
Illustration 17 g02212590
Always lap the valve against the valve seat after refacing the valve seat or after replacing the valve.
Apply a thin coat of lapping compound evenly to the valve face.Note: Do not allow the compound to adhere on the valve stem. Compound spreads more evenly if compound is mixed with a small amount of engine oil. Use medium-grain compound (120