345 MHPUC Mobile Hydraulic Power Unit Hydraulic System Relief Valve (Swing) - Test and Adjust Caterpillar


Relief Valve (Swing) - Test and Adjust
`
1.1. Preparation
2.1. Right Swing Motor
3.1. Left Swing Motor

Preparation

  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 1g01128644

    Pump compartment

    (1) Pressure tap (delivery pressure for drive pump)

    (2) Pressure tap (power shift pressure)

    (3) Pressure tap (delivery pressure for idler pump)

  1. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (3) .



    Illustration 2g01128646

    Left swing motor (bottom view)

    (4) Pilot manifold

    (5) Connector

  1. Disconnect connector (5) from pilot manifold (4) .

  1. Start the engine

    Note: Certain machines will default to "Economy Mode" at machine startup. Change to "High Hydraulic Power Mode" before performing the test procedure.

  1. Place the machine controls at the following settings: Power Mode, engine speed dial "10" and AEC switch OFF.

    Note: The engine will not reach maximum no-load speed until the hydraulic tank pressure has reached the operating level.

    ReferenceRefer 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).

    Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.




Illustration 3g01435105

Swing motors (top view)

(6) Left swing motor

(7) Right swing motor

(15) Relief valve (left swing motor)

(16) Locknut

(17) Adjustment plug

(18) Adjustment plug

(19) Locknut

(20) Relief valve (right swing motor)

(28) Relief valve (right swing motor)

(29) Locknut

(30) Adjustment plug

(31) Adjustment plug

(32) Locknut

(33) Relief valve (left swing motor)

Right Swing Motor

Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.

    Note: A temporary setting of the relief valve pressures for the left swing motor is required to see the relief valve pressures of the right swing motor.

  1. Loosen locknuts (16) and (19) on the left swing motor (6) . Turn adjustment plugs (17) and (18) by one quarter turn clockwise.

  1. Slowly move the swing control lever for a full right swing operation and check the pressure for relief valve (28) at pressure tap (3) .

  1. Return the swing control lever to the NEUTRAL position.

  1. Loosen locknut (29) on the right swing motor (7) . Turn adjustment plug (30) until the pressure gauge reading at pressure tap (3) is 31400 ± 1000 kPa (4555 ± 145 psi).

  1. Slowly move the swing control lever for a full left swing operation and check the pressure for relief valve (33) at pressure tap (3) .

  1. Return the swing control lever to the NEUTRAL position.

  1. Loosen locknut (32) on the right swing motor (7) . Turn adjustment plug (31) until pressure gauge reading at pressure tap (3) is 31400 ± 1000 kPa (4555 ± 145 psi).

  1. Tighten locknut (29) and locknut (32) to a torque of 155 ± 29 N·m (115 ± 21 lb ft).

Note: Turning adjustment plugs (30) and (31) clockwise increases the pressure. Turning adjustment plugs (30) and (31) counterclockwise decreases the pressure.

Note: Always make final pressure adjustment on the pressure rise.

Left Swing Motor

Note: Move the swing control lever slowly and ensure that the swing parking brake is operating properly.

    Note: After the adjustment of the right swing motor is complete, an adjustment of the relief valve pressures for the left swing motor is required to see the relief valve pressures of the left swing motor.

  1. Loosen locknut (16) and (19) on the left swing motor (6) . Turn adjustment plug (17) and (18) by one half turn counterclockwise.

  1. Slowly move the swing control lever for a full right swing operation and check the pressure for relief valve (20) at pressure tap (3) .

  1. Return the swing control lever to the NEUTRAL position.

  1. Loosen locknut (19) on the left swing motor (6) . Turn adjustment plug (18) until the pressure gauge reading at pressure tap (3) is 31400 ± 1000 kPa (4555 ± 145 psi).

  1. Slowly move the swing control lever for a full left swing operation and check the pressure for relief valve (15) at pressure tap (3) .

  1. Return the swing control lever to the NEUTRAL position.

  1. Loosen locknut (16) on the right swing motor (7) . Turn adjustment plug (17) until pressure gauge reading at pressure tap (3) is 31400 ± 1000 kPa (4555 ± 145 psi).

  1. Tighten locknut (16) and locknut (19) to a torque of 155 ± 29 N·m (115 ± 21 lb ft).

Note: Turning adjustment plugs (17) and (18) clockwise increases the pressure. Turning adjustment plugs (17) and (18) counterclockwise decreases the pressure.

Note: Always make final pressure adjustment on the pressure rise.

Information System:

3500 Engines Atmospheric Pressure Sensor - Remove and Install
3126B Petroleum Engine Injector Solenoid Circuit - Test
3126B Petroleum Engine Engine Pressure Sensor Open or Short Circuit - Test
3500B High Displacement Generator Set Engines Safety Messages
3126B Petroleum Engine 5 Volt Engine Pressure Sensor Supply Circuit - Test
3126B Industrial Engines E027 High Inlet Air Temperature Warning
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Pistons and Connecting Rods - Install
3508C, 3512C and 3516C Marine Engines Engine Speed/Timing Sensor - Remove and Install
3508C, 3512C and 3516C Marine Engines Engine Speed Sensor - Remove and Install
307D, 311D, 312D, 313D, 315D, 318D, 319D, 320D, 323D, 324D, 325D, 326D, 328D, 329D, 330D, 336D, 340D, 345D, 349D, 374D, 390D and M325D Excavators Air Conditioning and Heating General Information
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Pistons and Connecting Rods - Disassemble
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Lifter Group - Remove and Install
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Connecting Rod Bearings - Remove
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Connecting Rod Bearings - Install
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Crankshaft - Remove
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Crankshaft - Install
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Bearing Clearance - Check
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines V-Belts - Remove and Install
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Alternator - Remove and Install
3126B Industrial Engines E100 Low Engine Oil Pressure Warning
C7 Engines for Caterpillar Built Machines Water Pump - Test
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Electric Starting Motor - Remove and Install
345 MHPUC Mobile Hydraulic Power Unit Machine System Specifications Fuel Lines
C1.1, C1.5 and C2.2 Engines for Caterpillar Built Machines Pistons and Connecting Rods - Assemble