740 Ejector Articulated Truck Caterpillar

Ejector Control Valve - Test

Usage:

740 3F7

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NOTICE

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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat^® products. Dispose of all fluids according to local regulations and mandates.

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Table 1
Ejector Control Valve Test
Test	Specification	Actual
Proportional Solenoid Resistance	5 ± 0.3 Ohms at 25 °C (77 °F)

This story includes the following tests:

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Move the machine to a smooth, horizontal location that is away from operating machines and away from personnel.
Permit only one operator on the machine. Keep all other personnel away from the machine or in the operator sight.
Rotate the steering wheel to a NEUTRAL position.
Move the transmission control to park to engage the parking brake.
Lower or retract the implements.
Stop the engine.
Turn the key to the ON position, but do not start the engine.
Verify that the implement controls are UNLOCKED.
Move the control levers through the full range of travel several times. Moving the control levers should relieve any pressure that may be present in the implement hydraulic system.

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Illustration 1	g06206887
(1) Ejector control valve (2) Pilot control actuator (3) Pilot control actuator

Disconnect the wiring harness to the suspected proportional solenoid. Check the resistance between the two pins on each solenoid. The resistance should be 5 ± 0.3 Ohms at 25 °C (77 °F).
If the resistance is not 5 ± 0.3 Ohms, replace the proportional solenoid. Refer to Disassembly and Assembly for information on the ejector control valve.
If the resistance is 5 ± 0.3 Ohms, proceed to step 2.
Momentarily connect the proportional solenoid to the battery (24 V) and listen for movement of the core of the proportional solenoid. Do not maintain the connection to the battery (24 V) for more than 0.5 second.
If the core does not move, replace the proportional solenoid. Refer to Disassembly and Assembly for information on the ejector control valve.
Reinstall any components which were removed from the machine.

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Illustration 2	g06206887
(1) Ejector control valve (2) Pilot control actuator (3) Pilot control actuator

Perform Step 1 through Step 9 from the"Test Preparation" section.
Remove pilot control actuator (2) and pilot control actuator (3). The pilot control actuators are at each side of ejector control valve (1).
Inspect the stem and verify it will slide within the body of ejector control valve (1). Remove the stem from ejector control valve (1) and check for excessive wear or scoring. Also, check the inside ejector control valve (1) for contamination.
Remove any contamination from ejector control valve (1) and from the stem.
If the stem does not slide inside the ejector control valve or if the stem is damaged, the ejector control valve must be serviced.