LADDER GP 5152574 - Caterpillar

To prevent possible injury, make sure all of the air pressure is released from the air tank before you disconnect the test gauges and the hose assemblies.
Table 1
Required Tools    
Part Number    Description    Required Amount    
8T-0849     Pressure Gauge (0 to 2,000 kPa (0 to 290 psi)) (1)     1    
177-7861     Hose As     1    
6V-3966     Fitting As     1    
6V-4143     Coupler     1    
8T-4188     Union Adapter     1    
( 1 ) There is one 8T-0849 Pressure Gauge in the 1U-5481 Pressure Gauge Group .
Illustration 1 g00936366
Left Side of the Machine, Rear Compartment (1) Air tank (2) Drain line (3) Drain valve
Open drain valve (3) in order to release the air pressure from air tank (1) .
Remove drain line (2) from drain valve (3). Assemble 6V-3966 Fitting As to the open port for the drain line.
Assemble the following components and connect to 6V-3966 Fitting As : 6V-4143 Coupler, 177-7861 Hose As, 8T-4188 Union Adapter and 8T-0849 Pressure Gauge .
Start the engine. Allow the air pressure to increase to the cut out pressure.
Open drain valve (3) to the left section of air tank (1). Read the cut out pressure on the test pressure gauge.
Depress the service brake control (pedal) and release the pedal several times. Perform this action rapidly.
Read the cut-in pressure on the test pressure gauge.
Refer to Specifications, "Air Compressor Governor" for the appropriate cut out pressure and cut-in pressure.If necessary, make the following adjustment to the air compressor governor:
Illustration 2 g00932809
Remove cover (5) from the top of air compressor governor (4) .
Loosen the locknut on the adjustment screw.
Turn the adjustment screw counterclockwise in order to raise the cut-in pressure.
Turn the adjustment screw clockwise in order to lower the cut out pressure.
If the adjustment screw does not change the cut out pressure, the unloading valves in the air compressor are operating incorrectly.
If the difference between the cut-in pressure and the cut out pressure is incorrect, the air compressor governor is operating incorrectly.
Close drain valve (3) .
Stop the engine.
Depress the service brake control (pedal) and release the pedal several times. This will release the air pressure in the air tank.
Remove all test equipment. Install drain line (2) to the drain valve.