Massey Ferguson 0A.42.18 – Main tractor control network: External Hydraulic Valve 4 Issue

A malfunction associated with the 4th rear hydraulic remote (spool valve), typically caused by an electrical connection problem (short, open circuit, or communication failure) or a mechanical failure where the valve is sticking, jamming, or failing to actuate properly.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Check the wiring harness and connector going to External Valve 4 at the rear remote block for corroded pins, loose connections, or damaged wires (electrical cause).

2. 2

   Verify the hydraulic fluid (UTTO) level and condition, as contaminated fluid or clogged filters can cause the valve spool to stick.

3. 3

   Inspect the valve body and quick couplers for visible fluid leaks, which can cause a drop in pressure.

4. 4

   Check if the valve is physically jammed by debris by manually attempting to actuate the valve (if a manual override is present) to determine if the spool is seized (mechanical cause).

1. 1

   Safety First

   Lower all implements to the ground, turn off the tractor, disconnect the battery, and relieve all hydraulic system pressure before beginning work.

2. 2

   Access the Valve Block

   Locate the rear hydraulic remote stack and identify Valve 4 (usually the outermost or top/bottom valve depending on the stack orientation).

3. 3

   Disconnect Electronics

   Carefully unplug the electrical harness from the electric spool slice.

4. 4

   Remove the Valve

   Unbolt the specific spool slice from the hydraulic valve stack. Be prepared to catch residual hydraulic fluid.

5. 5

   Rebuild or Replace

   If leaking: Disassemble the valve and replace the internal O-rings and seals using an OEM repair kit. If electronically failed: Replace the entire electric spool slice unit.

6. 6

   Reinstallation

   Bolt the new or rebuilt valve back into the stack, ensuring all mating surfaces are clean and new seals are seated properly. Reconnect the electrical harness.

7. 7

   System Bleed and Programming

   Refill the hydraulic fluid to the proper level. If a new electric spool slice was installed, it will need to be programmed/calibrated to the tractor's ECU using a compatible Massey Ferguson diagnostic tool. Finally, clear the 0A.42.18 DTC from the system.