COUPLING AS 4980776 - Caterpillar

Table 1
Required Tooling    
Quantity     Part Number     Part Name    
1     4C-9017     Pressure Gauge    
1     4C-7156     Fitting    
1     4C-7253     Coupling    
1     197-8947     Adapter    
1     6V-9835     Swivel Tee    
2     4J-5477     O-Ring Seal    
Park the machine in a level area. Shut off the machine.
Remove the cover over the air pump.
Illustration 1 g03081236
Typical installation (1) Existing outlet hose (2) Air pump (3) Outlet from air pump
Disconnect the existing outlet hose (1) from the outlet of the air pump (3) .
Attach 6V-9835 Swivel Tee to the elbow at the outlet of the air pump (3) . Connect the hose to the center port on the tee.
Use the 197-8947 Adapter in order to connect the 4C-7253 Coupling to the remaining port on the tee.
Attach the 4C-7156 Fitting to the 4C-9017 Pressure Gauge .
Connect the pressure gauge and fitting to the coupler.
Start the machine. Activate the variable pitch fan. Check the pressure on the pressure gauge.
The pressure reading should rise through the purge cycle. After 20 seconds, the minimum pressure reading should reach 760 kPa (110 psi) due to the dead head condition. If the pressure reading is low, refer to "Possible Causes of Low Pressure".
Ensure that the fan blades return to the original blade angle. The sound of the air discharge should be heard at the end of the purge cycle. If the blades do not return to the original angle or the discharge cannot be heard, verify proper valve operation. Using the installed pressure gauge, from the previous steps, located on the down stream side of the valve, the delivered pressure must reach a minimum of 760 kPa (110 psi) during the fan purge cycle. If the pressure reading cannot be obtained, refer to "Possible Causes of Low Pressure". When the purge cycle is complete, the pressure should drop to 0 kPa (0 psi) in 5 seconds or less. If the pressure does not return to 0 kPa (0 psi) in 5 seconds or less, investigate valve and hose connections for pinch points or entrained debris. If lines are not pinched, clear of internal obstructions, replace the 188-2461 Solenoid Valve Gp . To verify proper fan purge operation, with engine off, use an independent source of compressed air, not exceeding 827 kPa (120 psi) @ 1.1 CFM maximum and connect to the hose assembly leading to the fan hub. The fan blades, upon application of compressed air will turn 180 degrees. If the blades do not rotate 180 degrees, remove fan and inspect for internal damage.Possible Causes of Low Pressure
Illustration 2 g03081296
(1) Outlet hose (2) 321-8191 Air Pump (3) Inlet hoseCheck inlet hose (3) . Ensure that the hose is not bent or clogged. In order to check for an obstruction in the hose, disconnect the hose from the pump. Activate the purge cycle for the fan. If the pressure delivered from the compressor does