Massey Ferguson A.4X.26 – Implement Control Module, Hydraulic Control Unit, or Transmission Control Unit (TCU): External Hydraulic Valve 4 Issue

Malfunction, restriction, or electrical connection problem associated with the 4th rear remote hydraulic spool valve. Indicates a failure in the valve's ability to actuate, a stuck spool, a pressure/flow discrepancy, or an electrical fault in the valve's solenoid/actuator.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S

1. 1

   Verify the hydraulic fluid (UTTO) level using the dipstick or sight glass on level ground. Check if the hydraulic/transmission filter is due for its 300–500 hour replacement, as a clogged filter can restrict flow.

2. 2

   Inspect the #4 remote valve block at the rear of the tractor for visible leaks, damaged couplers, or physical jamming.

3. 3

   Inspect the wiring harness and electrical connector plugging into the #4 spool valve solenoid for corrosion, frayed wires, or loose pins.

4. 4

   Use a hydraulic flow meter and pressure gauge at the #4 rear remote couplers to see if the valve is outputting the correct pressure compared to valves 1, 2, and 3.

1. 1

   Depressurize the System

   Lower all implements to the ground, turn off the engine, and cycle the hydraulic controls to relieve any residual pressure in the system.

2. 2

   Drain/Catch Fluid

   Place a drain pan beneath the rear remote valve assembly to catch escaping hydraulic fluid.

3. 3

   Disconnect Electrical & Hydraulic Lines

   Unplug the electrical harness connector from the #4 spool valve. Disconnect the hydraulic hoses/hardlines attached to the valve block.

4. 4

   Remove the Valve

   Unbolt the #4 external hydraulic valve slice from the main hydraulic valve stack.

5. 5

   Repair or Replace

   Disassemble the valve to replace internal O-rings, seals, or the spool detents, or mount the new OEM electronic spool valve slice to the valve block.

6. 6

   Reassembly

   Torque the mounting bolts to factory specifications. Reconnect the hydraulic lines and the electrical harness.

7. 7

   Fluid Top-Up & Calibration

   Top up the hydraulic system with OEM-recommended UTTO fluid. Use a compatible diagnostic tool (such as Jaltest AGV or Massey Ferguson dealer software) to assign the new spool valve its correct position and calibrate it to the tractor's CAN-bus system.

8. 8

   Test

   Start the tractor, check for leaks, and test the #4 remote with an implement to ensure full functionality.