416D, 420D, 424D, 428D, 430D, 432D, 438D and 442D Backhoe Loaders Hydraulic and Steering System Caterpillar

Show/hide table

Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system.

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, 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.

Note: Put identification marks on all lines, on all hoses, on all wires, and on all tubes for installation purposes. Plug all lines, all hoses and all tubes. This helps to prevent fluid loss and this helps to keep contaminants from entering the system.

Valve Identification

There is no main relief valve. The pressure spool of the compensator valve acts as a main relief. The pressure spool of the compensator valve limits the system pressure to 20700 ± 700 kPa (3000 ± 100 psi) for the 416D and 424D and 22800 ± 700 kPa (3300 ± 100 psi) for the 420D, 428D, 430D, 432D, and 442D.

Do not increase the pressure compensator valve in an attempt to set the line relief valves that are set above the pump compensator spool setting. The line relief valves are very sensitive to flow and the line relief valves cannot be accurately set with the hydraulic pump.

The line relief valves must be removed from the machine.

Prior to removing the line relief valve, perform the swing test, the test for the implement, and the test for the stabilizer cycle time. Then, perform the margin pressure test, the low pressure standby test and the high pressure stall test. If a function is still suspected, stall that function and listen for the line relief valve to open. If the line relief valve does not open, then the line relief valve is set above the system pressure. Check the line relief valve pressure settings in order to verify that the line relief valves are within the specifications.

Illustration 1	g01049840
This is the location of the backhoe control valve for the sideshift frame.

Illustration 2	g00752521
This is the location of the backhoe control valve for the center pivot frame. Remove the floorplates in order to gain access to the top of the backhoe control valve. Refer to Disassembly and Assembly, RENR7780, "Floorplates - Remove and Install".

Illustration 3	g00867713
This is the location of the loader control valve. Remove the floorplates in order to gain access to the top of the loader control valve. Refer to Disassembly and Assembly, RENR7780, "Floorplates - Remove and Install".

Pilot Operated Controls

Backhoe Controls

Note: (S/N: TDR1-UPWEP1-UPSMJ1-UPTBD1-UPBKC1-UPBMC1-UP)

Note: (S/N: BKC) has pilot backhoe controls and mechanical loader controls.

Illustration 4	g00752250
Four bank valves for the backhoe control. (1) Head end line relief valve for the stick control valve. (2) Head end line relief valve for the bucket control valve. (3) Right swing circuit line relief valve for the swing control valve. (4) Rod end line relief valve for the boom control valve. (5) Rod end line relief valve for the stick control valve. (6) Rod end line relief valve for the bucket control valve. (7) Left swing circuit line relief valve for the swing control valve. (8) Head end line relief valve for the boom control valve.

Illustration 5	g00780999
Five bank valves for the backhoe control. (1) Control valve for the extendable stick. (2) Head end line relief valve for the stick control valve. (3) Head end line relief valve for the bucket control valve. (4) Right swing circuit line relief valve for the swing control valve. (5) Rod end line relief valve for the boom control valve. (6) Rod end line relief valve for the stick control valve. (7) Rod end line relief valve for the Bucket control valve. (8) Left swing circuit line relief valve for the swing control valve. (9) Head end line relief valve for the boom control valve.

Illustration 6	g00781133
Six bank valves for the backhoe control. (1) Control valve for the extendable stick. (2) Head end line relief valve for the stick control valve. (3) Head end line relief valve for the bucket control valve. (4) Right swing circuit line relief valve for the swing control valve. (5) Rod end line relief valve for the boom control valve. (6) Auxiliary control valve. (7) Rod end line relief valve for the stick control valve. (8) Rod end line relief valve for the Bucket control valve. (9) Left swing circuit line relief valve for the swing control valve. (10) Head end line relief valve for the boom control valve.

Backhoe controls

Note: (S/N: BKC1-UPBMC1-UP)

Illustration 7	g00847065
Four bank valves for the backhoe control. (1) Head end line relief valve for the stick control valve. (2) Head end line relief valve for the bucket control valve. (3) Right swing circuit line relief valve for the swing control valve. (4) Rod end line relief valve for the boom control valve. (5) Rod end line relief valve for the stick control valve. (6) Rod end line relief valve for the Bucket control valve. (7) Left swing circuit line relief valve for the swing control valve. (8) Head end line relief valve for the boom control valve.

Illustration 8	g00847066
Five bank valves for the backhoe control. (1) Head end line relief valve for the extendable stick control valve. (2) Head end line relief valve for the stick control valve. (3) Head end line relief valve for the bucket control valve. (4) Right swing circuit line relief valve for the swing control valve. (5) Rod end line relief valve for the boom control valve. (6) Rod end line relief valve for the stick control valve. (7) Rod end line relief valve for the Bucket control valve. (8) Left swing circuit line relief valve for the swing control valve. (9) Head end line relief valve for the boom control valve.

Illustration 9	g00847068
Six bank valves for the backhoe control. (1) Head end line relief valve for the extendable stick control valve. (2) Head end line relief valve for the stick control valve. (3) Head end line relief valve for the bucket control valve. (4) Right swing circuit line relief valve for the swing control valve. (5) Rod end line relief valve for the boom control valve. (6) Auxiliary control valve. (7) Rod end line relief valve for the stick control valve. (8) Rod end line relief valve for the Bucket control valve. (9) Left swing circuit line relief valve for the swing control valve. (10) Head end line relief valve for the boom control valve.

Loader Controls

Illustration 10	g00752643
Two bank valves for the loader control. (1) Tilt control valve for the rod end line relief valve. (2) Tilt control valve for the head end line relief valve. (3) Steering priority valve

Illustration 11	g00752645
Three bank valves for the loader control. (1) Auxiliary relief valve. (2) Rod end line relief valve for the tilt control valve. (3) Head end line relief valve for the tilt control valve. (4) Steering priority valve

Mechanically Operated Controls

Backhoe controls

Illustration 12	g00757402
Six bank valves for the backhoe control. (1) Head end line relief valve for the extendable stick control valve (2) Head end line relief valve for the bucket control valve (3) Right swing circuit line relief valve for the swing control valve (4) Rod end line relief valve for the boom control valve (5) Rod end line relief valve for the stick control valve (6) Rod end line relief valve for the Bucket control valve (7) Left swing circuit line relief valve for the swing control valve (8) Head end line relief valve for the boom control valve

Illustration 13	g00757388
Five bank valves for the backhoe control. (1) Head end line relief valve for the extendable stick control valve (2) Head end line relief valve for the bucket control valve (3) Right swing circuit line relief valve for the swing control valve (4) Rod end line relief valve for the boom control valve (5) Rod end line relief valve for the stick control valve (6) Rod end line relief valve for the Bucket control valve (7) Left swing circuit line relief valve for the swing control valve (8) Head end line relief valve for the boom control valve

Illustration 14	g00757137
Four bank valves for the backhoe control. (1) Head end line relief valve for the stick control valve (2) Head end line relief valve for the bucket control valve (3) Right swing circuit line relief valve for the swing control valve (4) Rod end line relief valve for the boom control valve (5) Rod end line relief valve for the stick control valve (6) Rod end line relief valve for the Bucket control valve (7) Left swing circuit line relief valve for the swing control valve (8) Head end line relief valve for the boom control valve

Loader controls

Illustration 15	g00783671
Three bank valves for the loader control. (1) Rod end line relief valve for the tilt control valve (2) Head end line relief valve for tilt control valve (3) Steering priority valve (4) Auxiliary relief valve

Illustration 16	g00783661
Two bank valve for the loader control (1) Rod end line relief valve for the tilt control valve (2) Head end line relief valve for the tilt control valve (3) Steering priority valve

Relief Valve Test

1. Use the following Steps in order to test or check the appropriate relief valve setting:

2. Lower all of the work tools and the stabilizers to the ground.

3. Stop the engine.

4. Turn the key to the ON position and move all of the control levers to all of the positions. This will release the system pressure.

5. Turn the key to the OFF position.

6. Remove the line relief valve that will be tested.

Show/hide table



Illustration 17	g00752785

7. Secure 1U-5216 Manifold (1) in a suitable holding device.

8. Install two 030-8370 Adapters (3) and two 1P-2375 Couplers (4) in 1U-5216 Manifold (1) .

9. Attach two 1P-2376 Adapters (5) to two 8F-0024 Hose Assemblies (6) .

10. Install line relief valve (2) in 1U-5216 Manifold (1) .

11. Connect two 8F-0024 Hose Assemblies (6) , two 3B-7722 Bushings , and 7J-8611 Street Ell to 3S-6224 Electric Hydraulic Pump .

12. Connect 8T-0860 Gauge to 3S-6224 Electric Hydraulic Pump .

13. Turn the 3S-6224 Electric Hydraulic Pump to the ON position. Check for leaks at the connection.

Show/hide table

NOTICE
The 3S-6224 Electric Hydraulic Pump only has a 7.6 L (2 US gal) reservoir. Pump damage may result if the pump is operated with an empty reservoir.

14. Slowly increase the pressure. Record the pressure, when the line relief valve opens. Compare this pressure to Table 3, 4, 5 or6.

15. Stop the pump.
    Show/hide table

    Table 2

    Line Relief Valve Pressure Settings for 420D, 428D, 432D and 442D
    Cylinder	Circuit	Setting
    Auxiliary for the Loader	Head End for the Auxiliary Cylinder	24200 ± 350 kPa (3500 ± 50 psi)
    Loader Tilt Circuit for Single Tilt Machines	Rod End for the Dump Operation	27600 ± 350 kPa (4000 ± 50 psi)
    	Head End for the Tilt Back Operation
    Loader Tilt Circuit for Parallel Lift Machines	Rod End for the Tilt Back Operation	27900 ± 350 kPa (4045 ± 50 psi)
    	Head End for the Dump Operation	16200 ± 350 kPa (2350 ± 50 psi)

    Show/hide table

    Table 3

    Line Relief Valve Pressure Settings on the 416D and 424D
    Cylinder	Circuit	Setting
    Auxiliary for the Loader	Head End for the Auxiliary Cylinder	24200 ± 350 kPa (3500 ± 50 psi)
    Loader Tilt Circuit for the Single Tilt Machine	Rod End for the Dump Operation
    	Head End for the Tilt Back Operation

    Show/hide table

    Table 4

    Line Relief Valve Pressure Settings for 420D, 428D, 432D and 442D
    Cylinder	Circuit	Setting
    Backhoe Boom	Head End to LOWER	15200 ± 350 kPa (2200 ± 50 psi)
    	Rod End to RAISE	29000 ± 350 kPa (4200 ± 50 psi)
    Backhoe Swing	Rod End to Swing LEFT	22800 ± 350 kPa (3300 ± 50 psi)
    	Rod End to Swing RIGHT
    Backhoe Bucket	Head End of the Bucket Cylinder	27600 ± 350 kPa (4000 ± 50 psi)
    	Rod End of the Bucket Cylinder	28300 ± 350 kPa (4100 ± 50 psi)
    Backhoe Stick	Head End for retracting the Stick IN	26900 ± 350 kPa (3900 ± 50 psi)
    	Rod End for extending Stick OUT	24800 ± 350 kPa (3600 ± 50 psi)

    Show/hide table

    Table 5

    Line Relief Valve Pressure Settings on the 416D and 424D
    Cylinder	Circuit	Setting
    Backhoe Boom	Head End to LOWER	15500 ± 350 kPa (2250 ± 50 psi)
    	Rod End to RAISE	29000 ± 350 kPa (4200 ± 50 psi)
    Backhoe Swing	Rod End to Swing LEFT	22800 ± 350 kPa (3300 ± 50 psi)
    	Rod End to Swing RIGHT
    Backhoe Bucket	Head End of the Bucket Cylinder	27600 ± 350 kPa (4000 ± 50 psi)
    	Rod End of the Bucket Cylinder	28300 ± 350 kPa (4100 ± 50 psi)
    Backhoe Stick	Head End for retracting the Stick IN	22800 ± 350 kPa (3300 ± 50 psi)
    	Rod End for extending Stick OUT