PISTON 3879833 - Caterpillar

Note: Either Tooling (B) can be used. Use the Tooling that is most suitable.
Ensure that wiring harness are correctly routed and the cable straps are not over tightened. Over tightening of the cable straps will damage the wiring harness convoluting.
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Do not turn the crankshaft while the valve springs are removed.
Plug the apertures for the push rods in the cylinder head to prevent the entry of loose parts into the engine
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Inspect valve springs (10) for damage and for the correct length. Refer to Specifications, "Cylinder Head Valves" for more information.
If necessary, install a new valve stem seal (11) onto the valve guide.Note: The outer face of the valve guide must be clean and dry before installing the valve stem seal.
Install valve spring (10) onto the cylinder head. Position valve spring retainer (9) on valve spring (10).
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Improper assembly of parts that are spring loaded can cause bodily injury.To prevent possible injury, follow the established assembly procedure and wear protective equipment.
Ensure that the valve spring is compressed squarely or damage to the valve stem may occur.
Install Tooling (A) in the appropriate position on the cylinder head to compress valve spring (10).Note: Ensure that the electronic unit injector label code (12) is not damaged when Tooling (A) is compressed.
Apply sufficient pressure to Tooling (A) to install valve keepers (8).Note: Do not compress the spring so that valve spring retainer (9) touches valve stem seal (11).
Install valve spring keepers (8).
Carefully release the pressure on Tooling (A).
Repeat Step 2 through Step 7 for the remaining valve springs.
The valve spring keepers can be thrown from the valve when the valve spring compressor is released. Ensure that the valve spring keepers are properly installed on the valve stem. To help prevent personal injury, keep away from the front of the valve spring keepers and valve springs during the installation of the valves.
Remove Tooling (A).Note: If all valve springs require replacement, the procedure can be carried out on two cylinders at the same time. The procedure can be carried out on the following cylinders. 1 and 6, 2 and 5 and 3 and 4. Remember that the crankshaft must not be turned while the valve springs are removed. Ensure that all the valve springs are installed before changing from one pair of cylinders to the other pair of cylinders. If all valve springs do not require replacement, the springs must be replaced in pairs.
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Follow Step 10.c through Step 10.f to install a new harness assembly (3) to electronic unit injectors (2).
Position a new harness assembly (3) into the cylinder head.Note: Do not lubricate the O-ring seal.
Push harness assembly (3) into the cylinder head.
Install a new bolt (5) and tighten the bolt to a torque of 5.5 N m (49 lb in).
Connect plug (6) to harness assembly (3).
Use a deep socket to install connections (1) to electronic unit injectors (2). Use Tooling (C) to tighten the connections to a torque of 2.0