DEFLECTOR 1927692 - Caterpillar

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.
Problem: The Fan Clutch Does Not Lock Up Or The Fan Runs Slowly
Probable Cause
There is a faulty engine coolant temperature sensor or a brake oil temperature sensor.
Check the electrical system for the fan clutch. While the engine is operating, disconnect the fuse for the control system for the fan clutch. If the fan clutch is fully engaged, proceed to the next step. If the fan clutch is not fully engaged, proceed to step 2.
Check the engine coolant temperature sensor and the sensor for the brake oil temperature for correct operation. Stop the engine and turn the ignition key to the ON position. Use the multimeter probe to ground pin C of the engine coolant temperature sensor to the frame of the engine. Listen for the fan drive valve to “click”. If the fan drive valve clicks replace the engine coolant temperature sensor. If the fan drive valve does not click replace the brake oil temperature sensor.
There is a faulty fan drive valve.
Check that the line for the control pressure to the fan clutch is connected to the correct fitting on the fan clutch. Check that the line for the supply of lubrication oil is connected to the correct fitting on the fan clutch. Check that the line for drain oil is connected to the correct fitting on the fan clutch. If the oil lines are correctly connected to the fan clutch, replace the solenoid valve for the fan clutch. If the oil lines are not correctly connected to the fan clutch, reconnect the lines to the proper connection.
Check that the fan drive valve is not plugged.
Check that there is control pressure between the fan drive valve and the fan clutch. Check the pressure at high idle. The pressure should be 450 35 kPa (65 5 psi).Note: The pressure tap for checking that the fan is on the solenoid valve for the clutch. Refer to Illustration 3 of the Fan Drive System.Problem: 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 237-5130 Digital Multimeter Gp. 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 Ohms to 5 Ohms, proceed to the next step. If the resistance of the fan drive valve is not 1.5 Ohms to