559D and 579D Knuckleboom Loaders Caterpillar

Piston Motor (Swing Drive) Relief Valve Pressure - Test and Adjust

Usage:

559D KL5

Show/hide table

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 table

Personal injury can result from rotating and moving parts. Stay clear of all rotating and moving parts.
Never attempt adjustments while the machine is moving or the engine is running unless otherwise specified.
The machine must be parked on a level surface and the engine stopped.

Attach a "Do Not Operate" or similar warning tag to the start switch and controls before servicing, repairing, or making adjustments to the machine.

Show/hide table

Hot hydraulic oil under high pressure can remain in the components of the hydraulic system or the power train system after the engine has been stopped. The uncontrolled release of the hydraulic oil can cause sudden machine movement and can also result in the following conditions:

Burns
The penetration of body tissue
Other personal injury
Death

If hydraulic oil penetrates body tissue, the injury must be treated immediately by a doctor who is familiar with this type of injury. Use a board or a piece of cardboard to check for a hydraulic oil leak. Make sure that all of the attachments have been lowered to the ground and that all trapped pressure has been released from the hydraulic system and the power train system. Also, make sure that the hydraulic oil is cool before the removal of any components or lines. Remove the hydraulic oil filler cap only when the engine is stopped and the filler cap is cool enough to touch with your bare hand.

Specifications

Show/hide table

Table 1
559D Swing Dual Relief Pressure
Date	Equipment ID Code
Pressure	Setting	Actual
Swing Right	25855 ± 345 kPa (3750 ± 50 psi)
Swing Left	25855 ± 345 kPa (3750 ± 50 psi)
High Idle	1820 RPM

Show/hide table

Table 2
579D Swing Dual Relief Pressure
Date	Equipment ID Code
Pressure	Setting	Actual
Swing Right	25855 ± 345 kPa (3750 ± 50 psi)
Swing Left	25855 ± 345 kPa (3750 ± 50 psi)
High Idle	1820 RPM

Introduction

This information includes the following test:

Swing Dual Relief Pressure

This information includes the following adjustment:

Swing Dual Relief Pressure

Required Tools

Show/hide table




Illustration 1	g03176578
Tooling (A)

Show/hide table

Table 3
Tool	Item	Part No	Description	Qty
	A1	8T-0860	Pressure Gauge (0 TO 40,000-KPA (0 TO 5,800-PSI))	1
	A2	6V-3989	Fitting	1
	A3	6V-4143	Quick Connect Coupler	2
	A4	177-7860	Hose As (3.0 m (10 ft))	1
	A4	177-7861	Hose As (4.3 m (14 ft))	1
	A4	177-7862	Hose As (5.5 m (18 ft))	1
	-	-	30-mm wrench	1
	-	-	1-3/16" socket	1

Test Preparation

Note: This test requires the work of two technicians.

Note: Hydraulic oil temperature must be at or above 60° C (140° F) to perform this test.

Remove all personnel from the area before beginning this procedure.
Use extension hoses that will permit the gauge to be read from ground level alongside the machine.

Test Procedure

Note: Check swing dual relief pressures at high idle and with oil at operating temperature of 60° C (140° F).

Show/hide table




Illustration 2	g06192037
513-4730 Swing Drive Ar. (1) Swing Right (2) Swing Left

Show/hide table




Illustration 3	g06192055
513-4731 Swing Drive and Mounting Gp. (1) Swing Right (2) Swing Left

Secure the boom so that the turntable will not rotate. Connect a 0 to 40,000 kPa (0 to 5,800 psi) pressure gauge at the Swing Right test port (1).
Have the operator start the engine and bring engine to high idle.
Fully activate the Swing Right foot pedal.
Observe the gauge reading. If the reading is not to specification, the Swing Right dual relief valve must be adjusted. See following section.
Move the 0 to 40,000 kPa (0 to 5,800 psi) pressure gauge to the Swing Left test port (2).
Have the operator bring the engine to high idle.
Fully activate the Swing Left foot pedal.
Observe the gauge reading. If the reading is not to specification, the Swing Left dual relief valve must be adjusted. See following section.

Adjustment Procedure

Shut down engine and remove key.
Use a 30-mm wrench for the lock nut and a 1-3/16" socket for the adjusting screw.
Back off the lock nut and turn the adjusting screw in CW to increase the pressure reading. Turn the adjusting screw out CCW to decrease the pressure reading.
When the setting is to specification, tighten the lock nut while holding the adjusting screw.
Repeat steps 2 and 3 to ensure that the setting is still correct.
If no further tests are planned, have the operator shut down the engine. Remove the pressure gauge from the test fitting.