C9.3 Marine Engine Caterpillar

Removal Procedure

Note: M.C.S. regulated engines are equipped with thermowells which allow specific temperature sensors to be removed while the engine remains in operation. A heat conductive compound is used to ensure that an accurate temperature reading is achieved by the temperature sensor when installed in a thermowell.

Note: For the engines not equipped with a thermowell, drain the coolant level until the coolant is below the sensor. Refer to Operation and Maintenance Manual, "Cooling System Coolant (ELC) - Change" for the correct draining and filling procedures.

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Illustration 1	g06213630
Typical Example

1. Disconnect harness assembly (1).

2. Remove coolant temperature sensor (2) from thermowell (3) for the engines equipped with a thermowell (3). Use a clean towel to remove the heat transfer compound from coolant temperature sensor (2) and thermowell (3).
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   Illustration 2	g06213632

3. Remove O-ring seal (4) from the coolant temperature sensor.

Installation Procedure

1. Install coolant temperature sensor (2) in the reverse order of removal.

   1. For the engines equipped with a thermowell (3), apply 1.7 mL (0.06 oz) of Tooling (A) to inside of thermowell (3). This will result in the cavity being 50% full. It is important that the cavity is not overfull, to avoid hydraulic lock.

   2. Tighten coolant temperature sensor (2) to a torque of 20 ± 3 N·m (177 ± 27 lb in).