PL61 Pipelayer and D6K Track-Type Tractor Caterpillar

Show/hide table

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.

Illustration 1	g01336756

The Fan Runs Slowly

Probable Cause

1. There is a faulty engine temperature sensor.
   • Check the electrical system for the fan. Use Caterpillar Electronic Technican (Cat ET) to check for any active fault codes or any logged fault codes. Refer to Troubleshooting, KENR5390, "C6.6 Engines for Caterpillar Built Machines" for troubleshooting procedures.

2. There is restriction in the oil supply line or the solenoid valve.
   • Remove the solenoid valve and check for possible blockage.

The Fan Runs at Maximum Speed

Probable Cause

1. There is a faulty fan drive valve.
   • Check the fuse for the control system for the fan. 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.

2. 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. Check for wires that are flattened. Check the wire insulation for signs of nicks, abrasion, or cuts. Contact with the engine or any sharp points may damage the wire insulation. If the wires are not flattened and there are no signs of nicks or cuts, proceed to the next step. If the wires are flattened or there are signs of nicks or cuts, repair the wires that are damaged.

   • Check the connections for moisture or corrosion. Check that the connector seals and white sealing plugs are in place. Check that the wiring harness does not make a sharp bend out of the connector. A sharp bend in the harness deforms the connector seal. The deformation creates a point of entry for moisture. If there are no missing seals, and the wiring harness does not make any sharp bends out of the connector, proceed to the next step. If there are missing seals, or the wiring harness makes a sharp bend out of the connector, make a repair or replace the wiring harness or the connector.

   • Check the connector pins and sockets. Verify that pins and sockets are not damaged. Verify proper alignment of the pins and proper location of the pins in the connector. If the pins and the socket are not damaged and the pins are properly aligned in the connector, proceed to the next step. If the pins and the socket are damaged or the pins are not properly aligned in the connector, make any needed repairs.

   • Check individual pin retention into the socket. Use a new pin to check each socket. Insert the pin into each socket in order to check for a good grip on the pin by the socket. Use a new socket to check each pin. Insert the socket onto each pin in order to check for a good grip on the pin by the socket. If there is not good pin retention, make any needed repairs.

   Note: The electrical contacts and plugs are waterproof. However, there can be contamination on the contacts in the plug. Contamination on the contacts can cause localized heating. Before replacing a sensor or a valve, disconnect the plugs and wash the contacts with a contact cleaner.

   Note: The electrical connectors cannot be serviced. Replace the faulty component or a faulty harness.

   Note: Use a 1U-5804 Crimp Tool to connect the connector pins onto the wire. Do not solder pins or sockets.

Oil Leakage at the Front Seal or the Rear Seal of the Fan Motor

Probable Cause

1. The length of the fan mounting bolt is incorrect.
   • If the fan mounting bolts are too long and the bolts contact the pulley, then replace the bolts with the correct bolts.

2. The orifice that is installed in the oil inlet port is incorrect or missing.
   • Install the correct orifice. If the oil leak continues, replace the fan motor.

3. There is a restriction in the oil return line.
   • Remove the restriction in the oil return line.

4. There are leaking oil seals.
   • Rebuild the fan drive. Refer to the Disassembly and Assembly in this service manual.

5. There are leaking wear sleeves.
   • Rebuild the fan drive. Refer to the Disassembly and Assembly in this service manual.