Massey Ferguson A.20.28 – Hydraulic Control Module / Tractor Control Unit (TCU): External Hydraulic Valve 2 Issue

Malfunction, restriction, or electrical connection problem with the second remote hydraulic spool valve, resulting in slow, weak, or completely dead hydraulic response on that specific circuit due to pressure loss, a stuck spool, or a sensor/solenoid failure.

• 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

   Check hydraulic fluid and filters for contamination (dirt or metal shavings) and blockages.

2. 2

   Inspect quick couplers (female body halves and male tips) on the rear remotes for damage that could block oil flow.

3. 3

   Test electrical connections, wiring harness, and connector going to the Solenoid Valve Spool for Valve 2 for corrosion, loose pins, or frayed wires.

4. 4

   Check for a stuck spool by manually actuating the valve (if mechanically possible) to see if it is physically jammed by debris.

1. 1

   Depressurize the System

   Turn off the tractor. Cycle the hydraulic levers/joystick to relieve all residual pressure in the implement circuits.

2. 2

   Drain/Isolate Fluid

   Depending on the valve location (usually mounted directly onto the lift cover or rear valve stack), drain the hydraulic fluid below the level of the valve block to prevent massive fluid loss.

3. 3

   Remove the Faulty Solenoid/Spool

   Disconnect the electrical harness from External Valve 2. Unbolt the solenoid valve spool assembly from the main hydraulic block.

4. 4

   Clean and Inspect

   Check the valve bore for scoring or debris. If the bore is heavily scored, the entire valve section may need replacement.

5. 5

   Install New Parts

   Install the new solenoid valve spool (or complete valve section). Ensure all O-rings (e.g., lift cover O-rings) are seated correctly and lubricated with clean hydraulic fluid.

6. 6

   Reassemble and Test

   Reconnect the hydraulic lines and electrical harness. Replace the hydraulic filter and top off the hydraulic fluid. Start the tractor, let it idle, and test the remote valve with an implement to ensure proper pressure and flow. Clear the DTC using a compatible diagnostic tool.