Massey Ferguson A.51.1E – EHR / Hydraulic Control Unit: External Hydraulic Valve 5 Issue

The tractor's onboard diagnostic system detects a fault in the circuit or operation of the 5th external hydraulic remote valve. The underlying condition is typically an electrical connection problem (such as an open circuit, short to ground, or short to power at the solenoid), a faulty sensor signal, or a mechanical issue like a stuck spool valve due to internal wear or debris.

• 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

   Inspect the wiring harness and connector at External Hydraulic Valve 5 for rub points, corrosion, or disconnected pins

2. 2

   Test the solenoid coil resistance to check for an open circuit or ground integrity

3. 3

   Check for visible hydraulic fluid leaks around the valve, which indicate worn seals

4. 4

   Check if the valve is mechanically sticking or jamming due to debris or a broken return spring

5. 5

   Connect a hydraulic hand pump to the control valve port, pressurize to 2500 psi, and check if the pressure holds. If it drops and cannot be pressurized, oil is bypassing the spool, indicating a damaged spool, bore, or contamination.

1. 1

   Disconnect battery

   Disconnect the tractor's battery before beginning electrical or hydraulic work.

2. 2

   Relieve pressure

   Relieve all hydraulic system pressure.

3. 3

   Locate valve

   Locate External Hydraulic Valve 5 on the rear remote valve stack.

4. 4

   Disconnect connector

   Disconnect the electrical connector to the valve solenoid.

5. 5

   Replace solenoid coil

   If the electrical diagnostic test failed, replace the solenoid coil.

6. 6

   Remove valve

   If the valve is mechanically stuck or bypassing fluid, remove the hydraulic lines and unbolt the valve from the manifold block.

7. 7

   Disassemble and inspect

   Disassemble the valve on a clean workbench. Clean and inspect the spool and bore for scoring or contamination.

8. 8

   Replace seals

   Replace all O-rings and seals using a spool valve seal kit.

9. 9

   Replace valve assembly

   If the spool or valve body is heavily worn or damaged, replace the entire hydraulic valve assembly.

10. 10

    Reinstall and test

    Reinstall the valve, reconnect the hydraulic lines and electrical connector, restore battery power, and test the hydraulic remote for proper operation.