Massey Ferguson A.70.18 – Tractor Control Unit (TCU) or dedicated implement/hydraulic control module: External Hydraulic Valve 7 Issue

Indicates a fault within the circuit or mechanical operation of the 7th external hydraulic remote valve (spool valve) at the rear of the tractor, commonly caused by a connection problem, a voltage irregularity, or a failure of the electric spool slice solenoid.

• 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

   Locate the external hydraulic valve stack at the rear of the tractor and visually identify Valve 7.

2. 2

   Disconnect the electrical harness to Valve 7 and inspect the pins for corrosion, bent terminals, or moisture ingress.

3. 3

   Check the wiring harness leading to the valve for chafing, breaks, or shorts to ground.

4. 4

   Temporarily swap the electrical connection/solenoid with an adjacent working valve (e.g., Valve 6) to see if the fault code follows the valve or stays with the wiring harness.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to ensure no power is running to the hydraulic control modules.

2. 2

   Relieve Pressure

   Relieve all hydraulic pressure from the rear remotes before servicing the valve block.

3. 3

   Clean the Area

   Thoroughly clean the external hydraulic valve stack to prevent dirt from entering the hydraulic system during disassembly.

4. 4

   Address Wiring

   If the diagnostic check revealed a wiring issue, repair the damaged wire or replace the connector pigtail.

5. 5

   Replace or Rebuild the Spool Slice

   If the electric spool slice itself has failed, unbolt the faulty Valve 7 slice from the hydraulic stack. If using a repair kit, disassemble the slice and replace the internal seals and pilot pressure controls. If replacing the whole unit, install the new electric spool slice and torque the tie-bolts to OEM specifications.

6. 6

   Reassemble and Calibrate

   Reconnect the electrical harness. Some new electric spool slices require programming/calibration to the tractor's system upon installation.

7. 7

   Clear Codes

   Use a compatible Massey Ferguson diagnostic tool or interface device to clear the 0A.70.18 DTC from the system. Test the hydraulic remote for proper operation.