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.
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
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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. Prevent possible injury by performing the procedure that follows before working on the machine. |
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The drive shaft rotates between the torque converter and the transmission whenever the engine is running. Contact with the rotating shaft can result in personal injury or death. The rotating shaft is located under the implement and steering pumps. Do not allow personnel into the pump bay area behind the cab when the engine is running. |
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- Park the machine on a smooth level surface.
- Shift the STIC transmission direction control switch to the NEUTRAL position.
- Lower the bucket and/or the attachment to the ground. Lower the blade and/or the attachment to the ground.
- Engage the parking brake.
- Place blocks in front of the wheels and behind the wheels.
- Install the steering frame lock.
- Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.
Show/hide table
Table 1 Speed Range and Direction Energized Solenoids Clutches that are Engaged Third Speed Forward 3 and 2 3 and 2 Second Speed Forward 4 and 2 4 and 2 First Speed Forward 5 and 2 5 and 2 Neutral 3 3 First Speed Reverse 5 and 1 5 and 1 Second Speed Reverse 4 and 1 4 and 1 Third Speed Reverse 3 and 1 3 and 1
- Install a hose and a 4130 kPa (600 psi) pressure gauge on pressure tap (G) .
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| Illustration 1 | g00108018 |
Location of Solenoid Valves (1) Number 1 solenoid (REVERSE). (2) Number 2 solenoid (FORWARD). (3) Number 3 solenoid (THIRD SPEED). (4) Number 4 solenoid (SECOND SPEED). (5) Number 5 solenoid (FIRST SPEED). (D) Torque converter inlet pressure tap P3. (E) Speed clutch pressure tap P1. (G) Direction clutch pressure tap P2. | |
- Engage the parking brake and shift the transmission into neutral. Start the engine and operate the engine at low idle.
- Depress the right service brake pedal and hold the right service brake pedal. Release the parking brake. Press the downshift gear speed switch until the transmission is in first speed. Watch the pressure gauge and move the direction control switch from the NEUTRAL position to the FORWARD position.
The needle on the pressure gauge should drop. Then, the needle will return to the original pressure reading. With the transmission in FORWARD position, press the upshift gear speed switch through the remaining forward speed positions and return the switch to first speed. The same pressure drop should be noted in all speeds. This checks the operation of all the speed clutches.
- Depress the right service brake pedal and hold the right service brake pedal. Release the parking brake. Press the downshift gear speed switch until the transmission is in first speed. Move the direction control switch to the FORWARD position.
Watch the pressure gauge and move the direction control switch to the REVERSE position. The needle on the pressure gauge should drop. Then, the needle will return to the original pressure reading. Now, move the direction control switch to the FORWARD position. The same pressure drop should be observed. This checks the operation of both direction clutches.
If a pressure drop is noted, the solenoid and the related electrical circuit are functioning.
If a pressure drop is not noted, use a screwdriver 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.
Reference: For additional information on electrical system troubleshooting for the 992G Wheel Loader, refer to the Service Manual module for Systems Operation, Testing and Adjusting, SENR1372, "Power Train Electronic Control System".
Reference: For additional information on electrical system troubleshooting for the 854G Wheel Tractor, refer to the Service Manual module for Systems Operation, Testing and Adjusting, RENR2143, "Power Train Electronic Control System".