GEAR (64 teeth) 7N2291 - Caterpillar

Pressure Switch (Service Brake Oil)
Illustration 6 g01142383
The service brake oil pressure switch is an input of the Power Train/Chassis ECM. The switch signals the Power Train/Chassis ECM when the service brake is applied. Connector contact A connects to the ground circuit. Connector contact B connects to the Power Train/Chassis ECM J1-33. Connector contact C connects to the Power Train/Chassis ECM J1-34. When connector contact B is grounded, the service brake is applied. When connector contact B is open, the service brake is released.The Power Train/Chassis ECM records diagnostic codes that are associated with the pressure switch (service brake oil) as a CID 0298. A record of the diagnostic code is made while the machine is in operation.
Table 3
Status of the Service Brake Oil Pressure Switch    
Switch Position     N/C (1)
J1-34     N/O (2)
J1-33    
Pressure     Open     Closed    
No Pressure     Closed     Open    
( 1 ) N/C means Normally Closed.
( 2 ) N/O means Normally Open.ReferenceFor more information on the service brake pressure switch, refer to Systems Operation Troubleshooting, Testing and Adjusting, "Operator Present Function".Pressure Switch (Brake Accumulator Oil) for the Alert Indicator and the Brake Application
Illustration 7 g00775461
Alert Indicator
The brake accumulator oil pressure switch for the alert indicator is an input of the Power Train/Chassis ECM. The switch connects to connector contact J2-60. This is a normally open switch that closes when the oil pressure in the brake system is correct. Connector contact A connects to the ground circuit. Connector contact B connects to the Power Train/Chassis ECM J2-60. Connector contact C is not used. When the brake accumulator oil pressure decreases below a preset value, the pressure switch will open. The switch sends a signal to the Power Train/Chassis ECM. The Power Train/Chassis ECM sends the information via the Cat Data Link to the Caterpillar Monitoring System. The information from the Power Train/Chassis ECM activates the brake accumulator oil pressure alert indicator on the main display.The Power Train/Chassis ECM records diagnostic codes that are associated with the pressure switch (brake accumulator oil) for the alert indicator as a CID 1272. A record of the diagnostic code is made while the machine is in operation. Brake Application
The brake accumulator oil pressure switch for brake application is an input of the Power Train/Chassis ECM. The switch connects to connector contact J2-58. Connector contact A connects to the ground circuit. Connector contact B connects to the Power Train/Chassis ECM J2-58. Connector contact C is not used. When the brake accumulator oil pressure decreases below a preset value, the pressure switch will open. The switch sends a signal to the Power Train/Chassis ECM. The Power Train/Chassis ECM engages the parking brake.The Power Train/Chassis ECM records diagnostic codes that are associated with the pressure switch (brake accumulator oil) for the brake application as a CID 1612. A record of the diagnostic code is made while the machine is in operation. Front/Rear Service Brake and Retarder Oil Pressure Switch
Illustration 8 g00775520
The front service brake and retarder oil pressure