Massey Ferguson A.4X.21: External Hydraulic Valve 4 Issue

A malfunction in the tractor's 4th auxiliary/remote hydraulic control valve, typically related to an electromechanical failure, a stuck spool valve, a loss of pressure, or a connection problem on the hydraulic valve's CAN actuator/stepper motor.

• 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 the hydraulic fluid (UTTO) level and ensure the fluid is not dark, burnt-smelling, or milky (which indicates water contamination).

2. 2

   Check for a partially blocked hydraulic filter that could be restricting flow to the system.

3. 3

   Inspect the hydraulic valve block wiring harness. Check Connector 1 (Plus Valve), Connector 2 (Minus Valve), and Connector 3 (Safety Valve) for corrosion, damage, or loose connections.

4. 4

   Use a hydraulic gauge to test the system pressure at the remote couplers to pinpoint whether the issue is a weak pump, a failing relief valve, or the #4 control valve itself.

5. 5

   Inspect the external valve, O-rings, and hydraulic lines for external leaks or seepage.

1. 1

   Relieve Pressure

   Ensure the tractor is turned off, implements are lowered to the ground, and all hydraulic pressure is relieved from the system.

2. 2

   Drain Fluid

   If removing the valve block, drain the hydraulic fluid from the reservoir to prevent spills.

3. 3

   Disconnect Wiring

   Unplug the CAN actuator electrical connectors (Plus, Minus, and Safety valve solenoids) from the #4 valve.

4. 4

   Disconnect Hoses

   Remove the hydraulic hoses connected to the valve, including the Tank return line (T) and LS-hydraulic pressure line (P).

5. 5

   Remove the Valve

   Unbolt the #4 control valve assembly from the hydraulic valve stack/manifold.

6. 6

   Replace Seals/Valve

   If rebuilding, replace all internal O-rings and zero-leak valves. If replacing, install the new OEM control valve assembly.

7. 7

   Reassembly

   Bolt the valve back into place, reconnect the hydraulic lines, and plug in the wiring harness.

8. 8

   Fluid and Filter

   Install a new hydraulic filter and refill the system with clean OEM UTTO fluid (e.g., 10W40).

9. 9

   Test

   Start the tractor, allow the system to warm up, and test the #4 remote for proper operation and leak-free performance.