FAN AR-VARIABLE 2037802 - Caterpillar

Testing and Adjusting the Fan Motor Speed
Introduction
This test is designed to determine if the fan motor is adjusted to the correct rpm.
Sudden movement of the machine or release of oil under pressure can cause serious injury to persons on or near the machine.To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system.
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 Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Required Tools
The hydraulic test may be performed with the following test equipment:
Standard toolingStandard Tooling
Illustration 1 g00926346
Illustration 2 g00927235
Use the tools in Table 1 to complete the following test procedure.
Table 1
Required Tools (Standard Tooling)    
Tool    Item    Part Number    Description    Qty    
A     A1     1U-6605     Reflective Tape     1    
A2 1U-7771 (1)     Phototach     1    
B     -     4C-6500     Digital Thermometer     1    
( 1 ) Tool (A2) is part of the 1U-6602 Photo-Tachometer .Test Procedure
Illustration 3 g00926073
Fan Motor (1) Fan blade
Make sure that the engine is off and make sure that the parking brake is applied.
Place Tool (A1) on fan blade (1) .Note: You can apply Tool (A1) without removing the fan guard. Reach around the guard next to the fan motor in order to apply the tape to the fan blade.
Connect Tool (A2) to a 12 VDC power supply or a 24 VDC power supply. Aim the phototach at the reflective tape.
Start the engine and run the engine at high idle at 2310 50 RPM. Check the hydraulic temperature with Tool (B) until the hydraulic oil temperature is at a minimum of 38°C (100°F).
Read the fan speed on Tool (A2). The fan speed should be 1625 25 RPM.
If the fan speed is not correct, relief valve (4) on the fan motor must be adjusted.Adjusting Procedure
Illustration 4 g00926108
Fan Motor (2) Adjustment screw (3) Locknut (4) Relief valve
Stop the engine.
Place a wrench on locknut (3) and insert an allen wrench in the hex on the top of adjustment screw (2) .
Loosen the locknut while the allen wrench is held.
Increase the fan speed by turning the allen wrench clockwise. Decrease the fan speed by turning the allen wrench counterclockwise.
Tighten the locknut.
Start the engine and recheck the fan speed.
If the fan speed is correct, remove Tool (A2) .