Massey Ferguson A.80.18 – Onboard diagnostic system: External Hydraulic Valve 8 Issue

A malfunction, connection problem, or operational failure associated with the 8th external hydraulic remote/spool valve on the tractor. The tractor's onboard diagnostic system flags this when the valve fails to actuate correctly, which can be caused by electrical faults, mechanical binding within the spool valve, or hydraulic pressure issues.

• 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

   Verify that the hydraulic reservoir is full and the fluid is not contaminated.

2. 2

   Check the wiring harness and electrical connector going to the solenoid of External Hydraulic Valve 8 for corrosion, frayed wires, or a loose connection (common cause for electrical communication errors).

3. 3

   Inspect the spool valve block at the rear of the tractor for visible hydraulic fluid leaks, which could indicate blown O-rings or seals.

4. 4

   Determine if the valve is physically sticking in one direction due to internal scoring or debris in the spool valve (mechanical binding).

5. 5

   Perform a pressure test to verify if the issue is isolated to Valve 8 or if the entire hydraulic pump system is suffering from low pressure.

1. 1

   Depressurize the System

   Turn off the tractor and cycle the hydraulic controls to relieve any residual pressure in the system before beginning work.

2. 2

   Disconnect Electricals

   Unplug the electrical connector from the Valve 8 solenoid.

3. 3

   Remove Hydraulic Lines

   Disconnect the hydraulic hoses attached to the affected valve. Cap the lines immediately to prevent fluid loss and keep dirt out of the system.

4. 4

   Dismount the Valve

   Unbolt the external hydraulic valve assembly from the rear hydraulic block/diverter plate.

5. 5

   Rebuild or Replace

   To Rebuild: Disassemble the spool valve on a clean workbench. Inspect the spool and bore for scoring. Replace all internal O-rings and seals using an OEM spool valve repair kit. To Replace: If the valve body is cracked, heavily scored, or features a sealed electronic failure (common in some Bosch/Rexroth valves used on these platforms), replace the entire valve unit.

6. 6

   Reinstallation

   Mount the new or rebuilt valve back onto the tractor. Reconnect the hydraulic lines and the electrical harness.

7. 7

   Test and Bleed

   Top off the hydraulic fluid. Start the tractor and actuate the valve several times to bleed air from the system. Check for leaks and verify that the A.80.18 code has cleared.