Massey Ferguson 0A.40.26: External Hydraulic Valve 4 Issue

Indicates a malfunction, restriction, or electrical fault associated with the 4th external hydraulic remote (spool valve) on the tractor.

• 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

   Inspect the wiring harness and electrical connector at External Hydraulic Valve 4 for corrosion, loose pins, or damage.

2. 2

   Check the hydraulic/transmission fluid level and condition, looking for dirty oil or a blocked filter.

3. 3

   Inspect the spool valve for visible leaks, sticking, or jamming caused by internal wear or debris.

4. 4

   Check the remote couplers and hoses for damage or blockages that might cause a dead or weak hydraulic response.

1. 1

   Retrieve Codes

   Connect a compatible diagnostic tool to the tractor to verify code 0A.40.26 is active.

2. 2

   Resolve Electrical Faults

   If the connector to Valve 4 is loose or damaged, clean the contacts, repair the wiring, and securely reconnect it.

3. 3

   Service the Hydraulics

   If the fluid is contaminated, drain the system, flush it, and replace the hydraulic/transmission filter. Refill with OEM-spec UTTO fluid (e.g., 10W40).

4. 4

   Clean or Replace the Valve

   If the valve is sticking or jamming due to debris, remove the valve body, clean it thoroughly, and replace the internal seals. If the valve is mechanically failed or the internal solenoid is dead, replace the External Hydraulic Valve 4 assembly.

5. 5

   Clear and Test

   Use the diagnostic tool to clear the DTCs. Run the tractor, warm up the hydraulic fluid, and actuate the 4th remote to ensure proper pressure, flow, and no leaks.