| Pressure Specifications | ||
|---|---|---|
| Date | ||
| Serial Number | ||
| Engine Speed | (1500 ± 20 rpm) | |
| Relief Pressure Setting | Actual Setting | |
| Cooler Back Pressure Manifold | |
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| Tank Back Pressure Manifold | |
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The hydraulic system consists of two back pressure manifolds. One manifold is on the front of the hydraulic oil cooler and one is on the front of the hydraulic oil tank.
The back pressure is used to prevent the hydraulic system from losing positive pressure. If a vacuum is created, cavitation could occur resulting in damage to hydraulic system components.
The manifolds are set differently to allow for priority flow to the hydraulic oil cooler over the return filter elements.
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| Illustration 1 | g02571852 |
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Tooling (A) 198-4240 Digital Pressure Indicator Gp. | |
| Required Tools | ||||
|---|---|---|---|---|
| Tool | Item | Qty | Part Number | Description |
| A | 1 | 198-4240 | Digital Pressure Indicator Gp | |
| A1 | 1 | 198-4234 | Digital Indicator | |
| A2 | 1 | 198-4237 | Pressure Sensor Gp ( |
|
| A3 | 1 | 198-4236 | Adapter Cable As | |
- Clear all personnel from the machine and from the area around the machine.
- Start the engine.
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Illustration 2 g01162712 - Place the hydraulic lockout control lever in the UNLOCKED position.
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Illustration 3 g06012959 "Auto Throttle" ON as displayed beside the programmable button on the monitor. - Press the "OK" button on the monitor to set "Auto Throttle" ON.
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Illustration 4 g03094559 Parking brake control button on the machine control panel. - Push down on the parking brake control button to de-activate the parking brake.
Note: The green indicator light will be illuminated when the parking brake is de-activated.
- Position the machine on level ground. Check the visibility and adjust the mirrors for the best vision close to the machine.
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Illustration 5 g03094697 Swing brake control button on the machine control panel. - Push down on the swing brake control button to de-activate the swing brake.
Note: The green indicator light will be illuminated when the swing brake is de-activated.
- Increase the hydraulic oil temperature to
49° C to 60° C (120° F to 140° F) .Show/hide table
Illustration 6 g06012461 Stabilizer lower control button on the machine control panel. - Push the "All Stabilizer Lower" control button to lower all the stabilizers to the ground.
- Lower the work tool to the ground.
- Place the hydraulic lockout control lever in the LOCKED position.
- Stop the engine.
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Personal 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, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.
Dispose of all fluids according to local regulations and mandates.
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Illustration 7 g06004765 Back pressure diagnostic port is on the cooler back pressure manifold located in front of the hydraulic oil cooler on the right side of the machine.
(1) Diagnostic port - Connect tooling (A2)
3445 kPa (500 psi) to diagnostic port (1) that is on the cooler back pressure manifold.
- Start the engine.
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Illustration 8 g01162712 - Place the hydraulic activation control lever in the unlocked position.
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Illustration 9 g06012487 Engine Status Display Screen. - Set Engine RPM on the Engine Status Display Screen.
To access the "Engine Status" screen, press the "Machine Status" function button (F2) from the main display screen. Press the "Engine Status" function button (F2) from the "Machine Status" screen.
Use the "Up" and "Down" buttons to change engine speed by the "Throttle Rate Change" percentage.
Note: Refer to Table1 in this procedure for the correct speed.
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Illustration 10 g06022356 Main display. Show/hide table
Illustration 11 g06023432 Maintenance display screen. - To override "Hydraulic Warming" set the number to "7" (Override Hydraulic Warming) then press the "OK" Button
Note: To access the"Maintenance Display" screen, press the"Machine Status" function button (F2) from the engine status or main display screen. Then press the "Maintenance Display" button (OK).
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Illustration 12 g03792676 Typical PIN code box to access the maintenance display screen. Note: A Personal Identification Number (PIN) code entry box will pop up. The PIN id required to access the Maintenance Display. The default maintenance PIN code is "0000". Enter the PIN code using the function (Up, Down, and OK) buttons.
- Use the "Up" button to change the selection number, in the upper left corner of the display Push the "OK" button and "Enabled" will appear to the left of the overridden selection.
Press the (F1) button to return to the Main Display screen.
- Check the pressure reading for the cooler back pressure manifold.
Note: Refer to Table 1 in this procedure for the correct pressure.
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Illustration 13 g06004982 Cooler back pressure manifold (hydraulic oil cooler).
(2) Relief valve - Loosen the locknut on relief valve (2) for the cooler back pressure manifold.
- Turn the adjustment screw clockwise until the pressure stops changing.
- Turn the adjustment screw an extra one half turn and then tighten lock nut.
Note: Adjusting the relief valve on the cooler back pressure manifold will allow for the pressure of the tank back pressure manifold to be seen at the test port on the cooler back pressure manifold.
- Check the pressure reading for the tank back pressure manifold.
Note: Refer to Table 1 in this procedure for the correct pressure.
Note: This pressure is for the relief valve on the tank back pressure manifold that is on the front side of the hydraulic oil tank.
Refer to the Adjustment Procedure section to set the correct pressures.
Adjust the tank back pressure manifold (hydraulic oil tank) before adjusting the cooler back pressure manifold (hydraulic oil cooler) section .
Tank Back Pressure Manifold (Hydraulic Oil Tank)
- Loosen the locknut on relief valve (3) for the tank back pressure manifold.
- Turn the adjustment screw on the tank back pressure manifold until the pressure reading at the cooler back pressure manifold diagnostic port is within specification.
Note: Refer to Table 1 in this procedure for the correct pressure.
Note: Turn the adjustment screw clockwise to increase the pressure. Turn the adjustment screw counterclockwise to decrease the pressure.
Note: Always make the final pressure adjustments on the pressure rise.
- While the adjustment screw for relief valve (3) is being held, tighten the locknut.
- Verify that the pressure is within specification.
- Once the pressure for tank back pressure manifold has been adjusted within specification, proceed with cooler back pressure manifold (hydraulic oil cooler) pressure adjustment.
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| Illustration 14 | g06132618 |
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The tank back pressure manifold on the front of the hydraulic oil tank. (3) Relief valve | |
Cooler Back Pressure Manifold (Hydraulic Oil Cooler)
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| Illustration 15 | g06004982 |
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The cooler back pressure manifold on the front of the hydraulic oil cooler. (2) Relief valve | |
- Loosen the locknut on relief valve (2) for the cooler back pressure manifold.
- Turn the adjustment screw on the cooler manifold until the pressure reading is within specification.
Note: Refer to Table 1 in this procedure for the correct pressure.
Note: Turn the adjustment screw clockwise to increase the pressure. Turn the adjustment screw counterclockwise to decrease the pressure.
Note: Always make the final pressure adjustments on the pressure rise.
- While the adjustment screw for relief valve (2) is being held, tighten the locknut.
- Verify that the pressure is within specification.
- Clear the "Override Hydraulic Warming" on the Maintenance Display screen.
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Illustration 16 g06013015 - Press the "Down" button"Engine Idle" on the monitor main screen to reset engine speed.
