The component configuration for the parking brake function has changed from earlier M300C machines. The changes are indicated by the illustrations below. The end result remains the same. When the parking brake is ENGAGED, the machine will not move. This change takes place for the following serial number ranges.
- (BDX2001-UP)
- (BCZ2001-UP)
- (BEB2001-UP)
- (BDK2001-UP)
- (BDY2001-UP)
- (BDR2001-UP)
- (BDM2001-UP)
- (H2A1-UP)
- (H2B1-UP)
- (H2C1-UP)
- (H2D1-UP)
- (H2E1-UP)
- (H2F1-UP)
- (H2G1-UP)
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| Illustration 1 | g01149791 |
Block diagram of the parking brake functionality for machines in the following serial number ranges: BDR1-2000, BDM1-2000, BDX1-2000, BCZ1-2000, BDK1-2000, BDY1-2000 and BEB1-2000. | |
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| Illustration 2 | g01149787 |
Block diagram of the parking brake functionality for machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP. | |
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| Illustration 3 | g01149797 |
ECM connections for components involved for machines in the following serial number ranges: BDR1-2000, BDM1-2000, BDX1-2000, BCZ1-2000, BDK1-2000, BDY1-2000 and BEB1-2000. | |
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| Illustration 4 | g01149890 |
ECM connections for components involved for machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP. | |
The parking brake is ENGAGED on the machine with the use of a spring force that will lock the transmission in place in order to prevent movement. On machines that are equipped with a parking brake solenoid, The ECM will de-energize the solenoid in order to allow the spring force to ENGAGE the parking brake. On machines that are equipped with the two transmission solenoids, the ECM will de-energize both solenoids in order allow the spring force to ENGAGE the parking brake.
When the ECM determines that the parking brake must be DISENGAGED, the ECM will energize either the parking brake solenoid or one of the two transmission gear shift solenoids depending on the machine configuration (see above illustrations). This allows pilot oil to flow to the transmission which allows hydraulic pressure to overcome the force of the springs and DISENGAGE the parking brake.
When the parking brake is ENGAGED, the ECM will illuminate the LED indicator above the parking brake switch on the soft switch panel (SSP). The Monitor will illuminate the parking brake indicator.
The ECM will ENGAGE the parking brake when any of the following conditions take place:
- If the service brake limit switch contacts are open (service brake not locked) and the parking brake switch on the soft switch panel is pressed, the parking brake is ENGAGED.
- If the service brake limit switch contacts are open (service brake not locked) the left armrest is in the UP position, the parking brake is ENGAGED.
- If the machine hydraulic system pressure is low, the parking brake is ENGAGED.
The ECM will DISENGAGE the parking brake when any of the following conditions take place:
- If the limp home switch is ON.
- If the service brake limit switch contacts are closed (service brake locked) the parking brake will be DISENGAGED.
- If the parking brake is ENGAGED and the service brake limit switch contacts close (service brake pedal depressed), the ECM will DISENGAGE the parking brake until the service brake limit switch contacts open (service brake pedal released), then the ECM will ENGAGE the parking brake again.
- When the parking brake is ENGAGED and the parking brake switch on the SSP is pressed, The ECM will energize the solenoid(s) in order to DISENGAGE the parking brake.
If there is an active diagnostic code for the armrest switch or the service brake limit switch, the parking brake will be ENGAGED unless the service brake is locked or the machine is traveling as indicated to the ECM by the transmission output speed sensor.