Massey Ferguson 0A.42.26 – Tractor Control Unit (TCU) / Implement Control Module: External Hydraulic Valve 4 Issue

Malfunction, connection problem, or operational failure associated with the tractor's 4th external hydraulic remote (spool valve).

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Verify the hydraulic fluid level and ensure correct OEM UTTO fluid is used. Check if the hydraulic filter has been changed within the last 300–500 hours.

2. 2

   Inspect External Hydraulic Valve 4 for physical signs of damage, external leaks, or a stuck spool.

3. 3

   Inspect the wiring harness and electrical connector at the #4 valve solenoid for corrosion, broken wires, or loose pins.

4. 4

   Perform a pressure test using a hydraulic pressure gauge at the #4 remote coupler to check pump output against specifications.

1. 1

   Relieve Pressure

   Turn off the tractor, lower all implements to the ground, and cycle the hydraulic levers/switches to relieve all residual pressure in the system.

2. 2

   Clean the Area

   Thoroughly clean the area around the rear remote valve block to prevent dirt from entering the hydraulic system during disassembly.

3. 3

   Address Electrical Faults

   If the diagnostic check revealed a wiring issue, repair the damaged wires or replace the solenoid connector pigtail.

4. 4

   Remove the Valve

   If the electrical circuit is intact but the valve is unresponsive or leaking, disconnect the hydraulic lines and electrical harness from Valve 4. Unbolt the valve section from the hydraulic block.

5. 5

   Rebuild or Replace

   Depending on the severity of the internal wear, either rebuild the valve using an OEM seal/O-ring kit or replace the entire electronic spool valve assembly.

6. 6

   Reinstall

   Bolt the new or repaired valve back into the stack. Reconnect the hydraulic lines and plug in the electrical connector.

7. 7

   Fluid and Calibration

   Top off the hydraulic fluid. Start the tractor and check for leaks. Use a compatible Massey Ferguson diagnostic tool to clear the 0A.42.26 code and, if necessary, recalibrate the new valve.