VALVE GP-PITCH RELIEF 4T3089 - Caterpillar

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Do not check for leaks with your hands. Pin hole (very small) leaks can result in a high velocity oil stream that will be invisible close to the hose. This oil can penetrate the skin and cause personal injury. Use cardboard or paper to locate pin hole leaks.
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The Fan Clutch Does Not Lock Up, or the Fan Clutch Runs Slowly
Probable Cause
There is a faulty engine temperature sensor.
Check the electrical system for the fan clutch. Use Caterpillar Electronic Technican (Cat ET) to check for any active fault codes or any logged fault codes. Refer to Troubleshooting, SENR9503, "C-9 Engines for Caterpillar Built Machines" for troubleshooting procedures.
There is a restriction of the oil flow. There is a faulty solenoid valve.
The clutch plates are faulty or worn.
Replace the clutch plates.The Fan Runs Continuously
Probable Cause
There is a faulty fan drive valve.
Check the fuse for the control system for the fan clutch. Stop the engine and turn the ignition key to the OFF position. Inspect the fuse. If the fuse is not blown, proceed to the next step. If the fuse is blown, replace the fuse.
Check the resistance of the fan drive valve. Unplug the wiring to the fan drive valve. Use a 7X-1708 Multimeter Probe, a 7X-1709 Multimeter Probe, and a 6V-7070 Digital Multimeter. Place the Digital Multimeter on the Direct Current setting and measure the resistance across pin 1 and pin 2. If the resistance of the fan drive valve is 1.5 to 5 Ohms, proceed to the next step. If the resistance of the fan drive valve is not 1.5 to 5 Ohms, replace the fan drive valve.
There are faulty connectors and/or faulty wires.
Check that the connectors are locked together in the correct manner. Check that the two halves cannot be pulled apart. Inspect the connections in order to ensure that both sides of the sensor's connector are latched. If the connector is not cracked or broken and the connector locks, proceed to the next step. If the connector is cracked or broken or the connector will not lock, replace the connector.
Check the joint between the pin and wire by applying a 45 N (10 lb) pull to each pin. If the pin and the connector remain in the connector body, proceed to the next step. If the pin and the connector do not remain in the connector body, repair the pin and the connector.
Check all hold down clamps for the harness in order to verify that the harness is properly clamped. Check that the clamp is not compressing the harness. Compressing the harness may flatten the wires.