SPRING 1255071 - Caterpillar

Note: Use of a platform may be necessary to reach the gas admission valves.For the procedure to remove the gas admission valve, refer to the engine's Disassembly and Assembly.When you disassemble the gas admission valve, inspect the seals. Replace the seals, if necessary. Refer to this Operation and Maintenance Manual, "Gas Admission Valve Seals - Inspect/Replace".
Illustration 1 g00833978
Exploded view and section view of the parts for the gas admission valve (1) Retainer locks (2) Valve rotator (3) Outer valve spring (4) Inner valve spring (5) Valve guide (6) Support assembly (7) ValveTo recondition the gas admission valve, replace retainer locks (1), valve rotator (2), outer valve spring (3), inner valve spring (4), and valve (7) .Valve guide (5) will probably have very little wear. However, measure the inner diameter of the valve guide at both ends and the middle. The maximum allowable inner diameter of the valve guide at both ends and the middle is 9.538 mm (0.3755 inch). If any measurement exceeds this specification, replace the valve guide. If this is not possible, replace support assembly (6) and the valve guide.It is unlikely for support assembly (6) to require replacement. However, inspect the valve seat in the support assembly.
Illustration 2 g00833994
Angle and dimensions for the valve seat in the support assemblyIf the valve seat is worn, the valve seat can be slightly ground according to these specifications:
The angle for the valve seat is 44.75 0.5 degrees.
The gauge diameter of the valve seat within a maximum depth of 2.0 mm (0.079 inch) from the end of the support assembly is 39.75 mm (1.565 inch).Use some Prussian blue to verify complete contact of the valve in the valve seat.