Massey Ferguson 0A.41.26 – Tractor Control Unit (TCU) or Hydraulic Control Module: External Hydraulic Valve 4 Issue

Malfunction, performance issue, or connection problem with the 4th external hydraulic spool valve (also known as a remote valve) in the tractor's hydraulic system.

• 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
• 6400
• 6600
• 7400

1. 1

   Check Electrical Connections: Inspect the wiring harness and the 4-pin connector at Valve 4 for corrosion, loose pins, or wire damage.

2. 2

   Check Fluid Level and Condition: Ensure the fluid is at the correct level. If the fluid is dark, smells burnt, or looks milky (indicating water contamination), it must be flushed.

3. 3

   Inspect for Leaks: Check the external valve block for fluid leaks around the fittings or O-rings, which can cause pressure drops.

4. 4

   Test System Pressure: Use a hydraulic gauge to test the system pressure to rule out a failing hydraulic pump, a blocked hydraulic filter, or a relief valve issue.

1. 1

   Relieve Pressure

   Ensure the tractor is turned off and relieve all hydraulic system pressure before beginning work.

2. 2

   Disconnect Electronics

   Unplug the electrical harness connector from External Hydraulic Valve 4.

3. 3

   Clean the Area

   Thoroughly clean the area around the hydraulic valve block to prevent dirt or debris from entering the hydraulic system during removal.

4. 4

   Remove the Valve

   Unbolt the faulty spool valve from the hydraulic valve stack.

5. 5

   Install New Seals

   Always replace the O-rings/seals between the valve and the mounting block to prevent future leaks.

6. 6

   Install the New Valve

   Mount the replacement valve and torque the mounting bolts to the manufacturer's specifications.

7. 7

   Reconnect and Refill

   Reconnect the electrical harness. Check the hydraulic fluid level and top up with OEM-recommended UTTO fluid (e.g., 10W40 equivalent).

8. 8

   Clear the Code

   Use a compatible Massey Ferguson diagnostic tool to clear the 0A.41.26 code from the system.