322C Forest Machine Hydraulic System Relief Valve (Line) - Test and Adjust - Equipped with Boom Lowering Control Valves Caterpillar


Relief Valve (Line) - Test and Adjust - Equipped with Boom Lowering Control Valves
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1.1. Test
2.1. Adjustment (Boom Cylinder Head End)
3.1. Adjustment (Boom Cylinder Rod End)
4.1. Adjustment (Stick Cylinder)
5.1. Adjustment (Bucket Cylinder)

Table 1
Required Tools    
Part Number     Description     Qty    
8T-0861     Pressure Gauge (60000 kPa (8700 psi))     2    
8T-0856     Pressure Gauge (
6000 kPa (870 psi))    
1    

Note: A temporary setting of the main relief valve pressure is required before any line relief valve pressure setting is adjusted. Refer to the adjustment procedures in Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".

Test

  1. Position the machine on level ground.

  1. Stop the engine.

  1. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".



    Illustration 1g00666193

    Pump compartment

    (1) Pressure tap (right pump delivery pressure)

    (2) Pressure tap (left pump delivery pressure)

    (3) Pressure tap (power shift pressure)

  1. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (1) .

  1. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (2) .

  1. Connect a 6000 kPa (870 psi) pressure gauge to pressure tap (3) . This is used to monitor power shift pressure.

  1. Start the engine.

  1. Place the machine controls at the following settings: engine speed dial 10, AEC switch OFF and SmartBoom OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.

  1. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).



    Illustration 2g00672009

    Monitor

    (A) Message display

    (B) Keypad

    (C) Up key

    (D) Left key

    (E) Down key

    (F) Right key

    (G) Cancel key

    (H) Set key

    (I) OK key

    (J) Menu key

  1. Start Service Mode and input a fixed power shift pressure of 2860 kPa (415 psi).

    1. Press menu key (J) .

      Note: If more than thirty seconds pass between pushing the keys on the keypad, the menu mode will be cancelled and the previous display will be restored to message display (A) .

    1. Press down key (E) in order to highlight the menu item "SERVICE OPTIONS" on the message display. Press OK key (I) .

    1. Input the password "FFF2". Press left key (D) or right key (F) in order to change the position of the flashing character. Press up key (C) or press down key (E) in order to change the value of the flashing character. Press OK key (I) after the correct password is displayed.

    1. Press down key (E) once in order to highlight the second line on the message display.

    1. Press right key (F) repeatedly until "DEVICE TEST" appears on the message display.

    1. Press down key (E) in order to move down one line on the message display.

    1. Press right key (F) until the "PS PRV - FIXED" appears on the message display.

    1. Press down key (E) .

    1. Press OK key (I) . The display on line 4 of the message display will now change to a numeric value. These characters represent the power shift pressure (kPa).

    1. Press left key (D) or right key (F) in order to increase or decrease the numeric value that is displayed on line 4 of the message display. Pressing left key (D) one time decreases the power shift pressure 10 kPa (1.5 psi). Pressing right key (F) one time increases the power shift pressure 10 kPa (1.5 psi).

      Note: The value for power shift pressure on the monitor may not always match the pressure reading on the pressure gauge. Adjust the value on the monitor until the desired power shift pressure is attained on the pressure gauge that is connected to the pressure tap for power shift pressure. The actual power shift pressure must be 2860 kPa (415 psi) on the pressure gauge.

      Note: To prevent a change in power shift pressure during the relief valve adjustment, do not turn the engine start switch to the OFF position.

      Note: Refer to Service Manual, "Engine and Pump Electronic Control System" for additional information on Service Mode.

  1. The pressure setting for both the head end and the rod end of the boom cylinders and stick cylinder is 37200 ± 1000 kPa (5400 ± 145 psi). The pressure setting for both the head end and the rod end of the bucket cylinder is 36800 ± 1500 kPa (5350 ± 215 psi).



Illustration 3g00832742

(4) Line relief valve (left boom cylinder head end)

(5) Line relief valve (right boom cylinder head end)

(6) Boom lowering control valves

The line relief valves for the boom cylinder head ends are located on boom lowering control valves (6) .




Illustration 4g00671867

Main control valve (front view)

(7) Line relief valve (boom cylinder rod end)

(8) Line relief valve (bucket cylinder)

(9) Line relief valve (stick cylinder head end)

The following line relief valves are located on top of the main control valve: boom cylinder rod end, stick cylinder head end and bucket cylinder. The line relief valve for the bucket cylinder is located under the main control valves and opposite the line relief valve for bucket cylinder (8) .




Illustration 5g00922975

Main control valve (bottom view)

(10) Line relief valve (stick cylinder rod end)

(11) Stick drift reduction valve

Line relief valve (10) (stick cylinder rod end) is located on stick drift reduction valve (11) .

Adjustment (Boom Cylinder Head End)




    Illustration 6g00922988

    Boom lowering control valve

    (4) Line relief valve (left boom cylinder head end)

    (5) Line relief valve (right boom cylinder head end)

    (12) Locknut

    (13) Adjustment screw

    Note: In order to adjust relief valve (5) on the right boom lowering control valve, relief valve (4) on the left boom lowering control valve must be temporarily adjusted.

  1. Mark the location of adjustment screw (13) on relief valve (4) .

  1. Loosen locknut (12) on relief valve (4) on the left boom lowering control valve. Turn adjustment screw (13) clockwise by one quarter turn. Tighten locknut (12) .

  1. Move the joystick for the boom until the boom is at the full BOOM RAISE position (full extension of boom cylinders). Hold the joystick for the boom in this position.

  1. Check the pressure in the boom cylinder head end on the pressure gauge at pressure tap (1) .

  1. Return the joystick for the boom to the NEUTRAL position.

  1. The pressure gauge reading should be 37200 ± 1000 kPa (5400 ± 145 psi). If the pressure gauge reading at pressure tap (1) is not within the specification, adjust line relief valve (5) .

  1. In order to adjust line relief valve (5) , loosen locknut (12) and turn adjustment screw (13) until the pressure gauge reading at pressure tap (1) is 37200 ± 1000 kPa (5400 ± 145 psi).

    Note: Turn adjustment screw (13) clockwise in order to increase the pressure. Turn adjustment screw (13) counterclockwise in order to decrease the pressure.

    Note: Always make final pressure adjustment on pressure rise.

  1. Loosen locknut (12) on relief valve (4) on the left boom lowering control valve. Turn adjustment screw (13) counterclockwise by one quarter turn to the marked position. Tighten locknut (12) .

    Note: In order to adjust relief valve (4) on the left boom lowering control valve, relief valve (5) on the right boom lowering control valve must be temporarily adjusted.

  1. Mark the location of adjustment screw (13) on relief valve (5) .

  1. Turn adjustment screw (13) on relief valve (5) clockwise by one quarter turn. Tighten locknut (12) .

  1. Move the joystick for the boom to the full BOOM RAISE position. Hold the joystick for the boom in this position and check the pressure gauge reading at pressure tap (1) .

  1. Return the joystick for the boom to the NEUTRAL position.

  1. The pressure gauge reading should be 37200 ± 1000 kPa (5400 ± 145 psi). If the pressure gauge reading at pressure tap (1) is not within the specification, adjust line relief valve (4) that is on the left boom lowering control valve.

  1. In order to adjust line relief valve (4) , loosen locknut (12) and turn adjustment screw (13) until the pressure gauge reading at pressure tap (1) is 37200 ± 1000 kPa (5400 ± 145 psi).

    Note: Turn adjustment screw (13) clockwise in order to increase the pressure. Turn adjustment screw (13) counterclockwise in order to decrease the pressure.

    Note: Always make final pressure adjustment on pressure rise.

  1. Tighten locknut (12) on relief valve (4) .

  1. Loosen locknut (12) on relief valve (5) on the right boom lowering control valve. Turn adjustment screw (13) counterclockwise by one quarter turn to the marked position. Tighten locknut (12) .

Adjustment (Boom Cylinder Rod End)

    Note: In order to adjust the line relief valve pressure setting for the boom cylinder rod end, a temporary adjustment of the line relief valve for the bucket circuit must be performed. Line relief valve (8) for the bucket is located on top of the main control valve.




    Illustration 7g00343372

    Line relief valve (typical example)

    (14) Locknut

    (15) Adjustment screw

  1. Loosen locknut (14) on the line relief valve for the BUCKET CLOSE function. Turn adjustment screw (15) by one half turn in a clockwise direction. Tighten locknut (14) on the line relief valve for the bucket cylinder.

  1. Move the joystick for the bucket to the full BUCKET CLOSE position (left). Hold the joystick for the bucket in this position. At the same time, move the joystick for the boom until the boom is at the full BOOM DOWN position (full retraction of boom cylinders). Hold the joystick for the boom in this position.

  1. Check the pressure in the boom cylinder rod end on the pressure gauge at pressure tap (1) .

  1. Return the joystick to the NEUTRAL position.

  1. The pressure gauge reading should be 37200 ± 1000 kPa (5400 ± 145 psi). If the pressure gauge reading at pressure tap (1) is not within the specification, adjust line relief valve (7) that is on the main control valve.

  1. Loosen locknut (14) on the boom line relief valve. Turn adjustment screw (15) until the pressure gauge reading at pressure tap (1) is 37200 ± 1000 kPa (5400 ± 145 psi).

  1. Tighten locknut (14) on the boom line relief valve.

    Note: Turn adjustment screw (15) clockwise in order to increase the pressure. Turn adjustment screw (15) counterclockwise in order to decrease the pressure.

    Note: Always make final pressure adjustment on pressure rise.

  1. After completion of line relief valve adjustment for the boom cylinders, return the line relief valve pressure setting of the bucket to the specified pressure setting.

Note: If an appropriate location is not available to fully extend the boom cylinders, exchange the functions of the boom line relief valves. Remove the line relief valve for the boom cylinder head end and the line relief valve for the boom cylinder rod end from the main control valve. Exchange the location of the line relief valves. Adjust the pressure of the boom line relief valve that is now attached in the head end. After completion of line relief valve adjustment, return the respective line relief valves to the original locations.

Adjustment (Stick Cylinder)

  1. To adjust the line relief valve pressure setting of the stick cylinder rod end, move the joystick for the stick until the stick is at the full STICK IN position (full retraction of the stick cylinder). Hold the joystick for the stick in this position.

  1. Check the pressure in the stick cylinder rod end on the pressure gauge at pressure tap (2) .

  1. Return the joystick for the stick to the NEUTRAL position.

  1. The pressure gauge reading should be 37200 ± 1000 kPa (5400 ± 145 psi). If the pressure gauge reading at pressure tap (2) is not within the specification, adjust line relief valve (10) that is on the stick drift reduction valve.

  1. In order to adjust line relief valve (10) , loosen locknut (14) on the stick line relief valve. Turn adjustment screw (15) until the pressure gauge reading at pressure tap (2) is 37200 ± 1000 kPa (5400 ± 145 psi).

  1. To adjust the line relief valve pressure setting of the stick cylinder head end, move the joystick for the stick until the stick is at the full STICK OUT position (full extension of stick cylinder). Hold the joystick for the stick in this position.

  1. Check the pressure in the stick cylinder head end on the pressure gauge at pressure tap (2) .

  1. Return the joystick for the stick to the NEUTRAL position.

  1. The pressure gauge reading should be 37200 ± 1000 kPa (5400 ± 145 psi). If the pressure gauge reading at pressure tap (1) is not within the specification, adjust line relief valve (9) that is on the main control valve.

  1. In order to adjust line relief valve (9) , loosen locknut (14) on the stick line relief valve. Turn adjustment screw (15) until the pressure gauge reading at pressure tap (2) is 37200 ± 1000 kPa (5400 ± 145 psi).

  1. After completion of line relief valve adjustment, tighten locknut (14) .

Note: Turn adjustment screw (15) clockwise in order to increase the pressure. Turn adjustment screw (15) counterclockwise in order to decrease the pressure.

Note: Always make final pressure adjustment on pressure rise.

Adjustment (Bucket Cylinder)

  1. To adjust the line relief valve pressure setting of the cylinder head end, move the joystick for the bucket until the bucket is at the full BUCKET CLOSE position (full extension of bucket cylinder). Hold the joystick for the bucket in this position.

  1. Check the pressure in the cylinder head end on the pressure gauge at pressure tap (1) .

  1. Return the joystick for the bucket to the NEUTRAL position.

  1. The pressure gauge reading should be 36800 ± 1500 kPa (5350 ± 215 psi). If the pressure gauge reading at pressure tap (1) is not within the specification, adjust line relief valve (8) that is on the main control valve.

  1. In order to adjust the relief valve, loosen locknut (14) on the line relief valve. Turn adjustment screw (15) until the pressure gauge reading at pressure tap (1) is 36800 ± 1500 kPa (5350 ± 215 psi).

  1. To adjust the line relief valve pressure setting of the cylinder rod end, move the joystick for the bucket until the bucket is at the full BUCKET OPEN position (full retraction of bucket cylinder). Hold the joystick for the bucket in this position.

  1. Check the pressure in the cylinder rod end on the pressure gauge at pressure tap (1) .

  1. Return the joystick for the bucket to the NEUTRAL position.

  1. The pressure gauge reading should be 36800 ± 1500 kPa (5350 ± 215 psi). If the pressure gauge reading at pressure tap (1) is not within the specification, adjust the line relief valve that is on the bottom of the main control valve.

  1. Loosen locknut (14) on the line relief valve. Turn adjustment screw (15) until the pressure gauge reading at pressure tap (1) is 36800 ± 1500 kPa (5350 ± 215 psi).

  1. After completion of line relief valve adjustment, tighten locknut (14) .

Note: Turn adjustment screw (15) clockwise in order to increase the pressure. Turn adjustment screw (15) counterclockwise in order to decrease the pressure.

Note: Always make final pressure adjustment on pressure rise.

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