VALVE GP-CHECK & RELIEF 5181312 - Caterpillar

Failure to perform the inspection at less than 4500 hours will not void the emission-related warranty.
The C27 Generator Set has three different speed sensors.
Illustration 1 g02143194Two speed/timing sensors (1) and (2) are mounted in the front housing. Both of these sensors are pulled into position by bolts.
Remove the speed/timing sensors from the front housing. Check the condition of the plastic end of the speed/timing sensors for wear and/or contaminants.
Clean the metal shavings and other debris from the face of the speed/timing sensors. Use the procedure in the Service Manual in order to calibrate the speed/timing sensors.
Illustration 2 g02144384The third speed/timing sensor has a threaded end, and screws directly into the flywheel housing.
Illustration 3 g01184155
Remove the sensor. Inspect the condition of the end of the magnet. Look for signs of wear and contaminants.
Clean any debris from the face of the magnet.
Check the tension of the sliphead. Gently extend sliphead (4) for a minimum of 4 mm (0.16 inch). Then push back the sliphead. When the sliphead has the correct tension, at least 22 N (5 lb) of force is required to push in the sliphead from the extended position.
The sliphead must be fully extended when the speed/timing sensor is installed so that the sensor maintains the correct clearance with the speed-timing wheel. If the correct clearance is not maintained, the signal from the sensor will not be generated.Do not install the sensor between the teeth of the speed-timing wheel. Damage to the sensor would result. Before installing the sensor, ensure that a tooth of the wheel is visible in the mounting hole for the sensor.
Install the engine speed/timing sensor.
Ensure that a tooth on the speed-timing wheel is visible in the mounting hole for the sensor.
Extend sliphead (2) by a minimum of 4 mm (0.16 inch).
Coat the threads of the sensor with 4C-5597 Anti-Seize Compound. Note: The sliphead is designed to contact a tooth during the first revolution of the speed-timing wheel. For the maximum allowable clearance between the sliphead and the tooth, refer to the engine's Specifications manual.
Install the sensor. Tighten the sensor to 40 5 N m (30 4 lb ft).