"Main Pump (Minimum Displacement) - Test and Adjust" | |||
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Date: | Machine Serial Number: | ||
Model | M314F | M316F | |
Machine Settings | Speed dial "10"
AESC switch OFF Power mode ON |
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Main Pump Pressure | |
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Margin Pressure | |
This procedure verifies that the main pump is operating properly provided that the minimum displacement of the main pump is adjusted properly.
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Illustration 1 | g02726620 |
Required Tools | ||||
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Tool | Item | Qty | Part
Number |
Description |
B | B1 | 2 | 8T-0861 | Pressure Gauge
|
B2 | 2 | 6V-3989 | Fitting | |
B3 | 4 | 6V-4143 | Quick Connect Coupler | |
B4 | 2 | 177-7860 | Hose As
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Minimum Displacement Screw Length | |
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Machine Model | Length |
M314F | |
M316F | |
The following test is a rough check for the minimum displacement setting. To perform an exact test of the minimum displacement setting, proceed to "Test Procedure".
- Remove the cap from minimum displacement screw (1).
- Measure the length of the minimum displacement screw (1) from the end of the minimum displacement screw to the top of the nut. Compare the length to the value in Table 3.
- Install the cap onto minimum displacement screw (1).
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Illustration 2 | g06034952 |
Main pump (typical example) (3) Minimum adjustment screw |
- Clear all personnel from the machine and from the area around the machine.
- Start the engine.
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Illustration 3 g02449876 Engine speed dial - Set the engine speed dial at "10".
- Lower the left console.
- Position the machine on level ground. Check the visibility and adjust the mirrors for the best vision close to the machine.
- Fully depress the service brake pedal until the service brake pedal locks mechanically.
- Increase the hydraulic oil temperature to
46° C to 60° C (115° F to 140° F) . - Fully extend the bucket cylinder and place the bucket on the ground.
- Stop the engine.
- Release the pressure in the hydraulic system.
Note: Refer to Testing and Adjusting, "System Pressure - Release".
- Raise the left console.
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Illustration 4 g06037111 The pressure tap is on the left side of the machine behind the front access door.
(1) Main pump pressure tap
(2) Load sense pressure tab - Attach Tooling (B2)
60,000 kPa (8,702 psi) pressure sensor to main pump pressure tap (1) and load sense pressure tab (2).Show/hide tablePersonal injury can result from hydraulic oil pressure and hot oil.
Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.
Make sure all of the attachments have been lowered, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
Show/hide tableNOTICE Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.
Refer to Special Publication, NENG2500, "AVSpare Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in AVSpare machines.
Dispose of all fluids according to local regulations and mandates.
- Start the engine.
- Set the engine speed dial at "10".
- Lower the left console.
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Illustration 5 g02552721 Power mode control button located on the soft panel switch - Push down on the power mode control button in order to activate power mode.
Note: The indicator light will be illuminated when power mode is activated.
- Use the Monitor in the cab in order to disable the Automatic Engine Speed Control.
- Select the "Performance" menu from the main menu on the monitor.
- Select "AESC Status" from the "Performance" menu and change the value to "Inactive".
- Press the "OK" key.
Show/hide tableIllustration 6 g03722432 Hydraulic modulation switch on left joystick Show/hide tableIllustration 7 g06186138 Hydraulic modulation aggressive mode (monitor display) - Select the hydraulic modulation mode as aggressive. Press the lower front switch on the left joystick to select the hydraulic modulation mode.
- The air conditioning should be turned off for the following test.
- Release the service brake pedal.
- Verify the main pump pressure at pressure tap (1) and load sense pressure tap (2).
- Compare pressures with the main pump pressure and margin pressure on Table 1.
Note: The margin pressure is the difference between main pump pressure and load sensing signal pressure.
- If the pressures are not within tolerances, then adjust minimum displacement adjustment screw. Refer to Section "Adjustment Procedure".
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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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Illustration 8 | g06034952 |
Main pump (typical example) (3) Adjustment screw |
- Remove the cap from adjustment screw (3).
- Turn adjustment screw (9) clockwise in order to increase the minimum displacement and turn adjustment screw (3) counterclockwise in order to decrease the minimum displacement.
Note: Always make the final adjustments as the flow increases.
- Install the cap onto adjustment screw (3).