Hearing the click of a solenoid or using a screwdriver to check that the solenoid coil is energized does not ensure that the solenoid plunger has shifted. The following test will determine if the solenoid plunger is shifting.
| Required Tools | ||
| Part Number | Description | Quantity |
| 1U-5481 | Pressure Gauge Group | 1 |
| 1U-5482 | Pressure Adapter Group | 1 |
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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
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Before you start the test procedure, complete the following procedure:
- Machine Preparation for Troubleshooting
Reference: For additional information on preparing the machine for troubleshooting, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
| Speed Range and Direction | Energized Solenoids | Engaged Clutches |
| First Speed Forward | 3 and 4 | 1 and 6 |
| Second Speed Forward | 1 and 4 | 2 and 6 |
| Third Speed Forward | 3 and 5 | 1 and 4 |
| Fourth Speed Forward | 1 and 5 | 2 and 4 |
| Fifth Speed Forward | 1 and 6 | 2 and 5 |
| Neutral | - | - |
| First Speed Reverse | 2 and 4 | 3 and 6 |
| Second Speed Reverse | 2 and 5 | 3 and 4 |
| Third Speed Reverse | 2 and 6 | 3 and 5 |
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| Illustration 1 | g00703652 |
View of the Transmission Solenoid Valve The operator's cab has been removed for clarity. | |
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| Illustration 2 | g00565271 |
Location of Solenoid Valves (1) No. 1 solenoid (HIGH FORWARD). (2) No. 2 solenoid (REVERSE). (3) No. 3 solenoid (LOW FORWARD). (4) No. 4 solenoid (FIRST SPEED). (5) No. 5 solenoid (SECOND SPEED). (6) No. 6 solenoid (THIRD SPEED). (AA) P2 pressure tap. | |
- Install the correct hose assembly 1U-5482 Pressure Adapter Group on P2 pressure tap (AA). Attach the opposite end of the hose assembly to a 4000 kPa (600 psi) pressure gauge.
- Engage the parking brake. Shift the transmission direction control switch to the NEUTRAL position. Start the engine and operate the engine at low idle.
- Depress the service brake pedal and hold the service brake pedal. Release the parking brake. Watch the pressure gauge and move the transmission direction control switch to the FORWARD position from the NEUTRAL position.
The needle on the pressure gauge should drop. Then, the needle will return to the original pressure reading. With the transmission in the FORWARD position, shift through the remaining forward speed positions and return the speed selector to the FIRST SPEED position. The same pressure drop should be noted in all speeds. This checks the operation of all the speed clutches.
- Perform Step 3 for all reverse speeds. The same pressure drop should be noted in all reverse speeds.
If a pressure drop is noted, the solenoid and the related electrical circuit are functioning correctly.
If a pressure drop is not noted, use a screwdriver in order to check that the solenoid coil is energized. If the screwdriver is attracted to the solenoid coil, this indicates that the solenoid coil is energized. The problem is in the solenoid cartridge. The problem could be a bent solenoid stem, a screen that is dirty or plugged, or a spring that is weak or broken.
If the screwdriver does not indicate that the solenoid coil is energized, the problem is in the electrical circuit.
Note: For additional information about troubleshooting the electrical system, refer to Testing and Adjusting, "Power Train Trobleshooting" and Schematic, "525B & 535B Wheel Skidder Electrcial System" for the machine that is being serviced.