PINION AS 1058586 - Caterpillar

Ignition systems can cause electrical shocks. Avoid contacting the ignition system components and wiring.Do not attempt to remove the valve covers when the engine is operating. The transformers are grounded to the valve covers. Personal injury or death may result and the ignition system will be damaged if the valve covers are removed during engine operation. The engine will not operate without the valve covers.
Maintenance of the spark plugs is required in order to achieve the following benefits:
Normal fuel consumption
Normal level of emissions
Maximum service life of the spark plugsThe service life of the spark plugs is affected by fouling due to deposits from the oil and by peak voltage. Maintenance of the ignition system is also affected by voltage. Higher voltage is required by higher inlet manifold air pressure and a higher compression ratio. Higher voltage reduces the service life of components such as spark plugs, wires, and transformers.Removing the Spark Plug
Illustration 1 g00787369
(1) Bolt
(2) Valve cover
(3) O-ring seal
Remove bolts (1). Remove valve cover (2). Inspect O-ring seal (3). If the seal appears to be worn or damaged, discard the seal and use a new seal for assembly.
Pulling on the wiring harness may break the wires. Do not pull on the wiring harness.
Illustration 2 g00787367
(4) Wiring harness
(5) Transformer
(6) Lip seal
(7) Spark plug
Disconnect wiring harness (4) from transformer (5). Be careful to completely depress the retainer clip away from the connector. Pull transformer (5) straight away from the cylinder head.
Inspect lip seal (6). If the seal is worn or damaged, discard the seal and use a new seal for assembly.
Illustration 3 g00787371
(8) O-ring seal
Inspect O-ring seal (8). If the seal is hard, cracked, or melted, install a new seal.
Pressurized air can cause personal injury. When pressurized air is used for cleaning, wear a protective face shield, protective clothing, and protective shoes.
Note: Excessive buildup of oil in the spark plug well is an indication of a damaged lip seal on the transformer. If this condition is found, clean the surface of the seal groove. Replace seal (6).
Debris may have collected in the spark plug well. Thoroughly remove any debris. Use compressed air. The maximum air pressure for cleaning purposes must be below 207 kPa (30 psi). Ensure that the area around the spark plug is clean and free of dirt and debris.
Use a 177.8 mm (7/8 inch), 4C-4601 Spark Plug Socket, an extension, and a breaker bar to loosen spark plug (7). After the spark plug has been loosened, use the socket and extension to remove the spark plug by hand in order to detect problems with the threads. After the spark plug has been removed, discard the used spark plug gasket. If the spark plug resists removal by hand, apply penetrating oil to the threads. To help the oil penetrate the threads, turn the spark plug back and forth until the spark plug is loose.If the spark plug cannot be removed by hand, clean the threads with 9U-7511 Spark Plug Seat Cleaner. This tool scrapes debris from the seat and