CAP 1794527 - Caterpillar

When opening the drain valve, wear protective gloves, protective face shield, protective clothing and protective shoes.Pressurized air could cause debris to be blown and result in personal injury.
Do not exceed an air pressure of 930 35 kPa (135 5 psi). Exceeding the specified limit can damage the air system components.
Table 1
Required Tools
Part Number Description Required Amount
6V-3966 Fitting As 1
198-4240 Digital Pressure Indicator 1
Release the air pressure from the air tanks.
Install a 6V-3966 Fitting As after the drain valve of the "Service Brake and Retarder Air Tank".
Connect 198-4240 Digital Pressure Indicator to 6V-3966 Fitting As.
Start the engine.
Record the pressure when the "Air Compressor" cuts out.
Repeatedly apply the "Brake Pedal" until the air pressure drops and the governor activates. This pressure is the cut-in pressure. Record this pressure.
If, the cut-out pressure is not 930 35 kPa (135 5 psi) and the cut-in pressure is not 758 kPa (110 psi), continue to Step 8. If the pressures are correct, continue to Step 13.
Illustration 1 g06096158
(1) Cover
Remove cover (1) at the top of the governor.Note: The governor is on the side of the "Air Compressor".
Loosen the adjusting screw locknut under the cover.
Turn the adjusting screw counterclockwise to increase the cut-out pressure setting to 930 35 kPa (135 5 psi). If you need to decrease the cut-out pressure setting, turn the adjusting screw clockwise.
Tighten the adjusting screw locknut to hold this adjustment.
Repeat Steps 4 through 7.Note: If the cut-out pressure has not changed, then check for bad "Unloading Valves". The "Unloading Valves" are located in the cylinder head of the air compressor. If, the difference between the cut-out pressure and the cut-in pressure is not within the specification range , check the condition of the governor.
Operate the engine until the cut-out pressure is reached. The reading on the "Air Pressure Gauge" on the machine must be equal to the reading on the test gauge. If the pressure difference is more than 35 kPa (5 psi), install a new air pressure sensor on the machine.
Stop the machine. Remove all test equipment.