Massey Ferguson A.20.27 – Onboard diagnostic system: External Hydraulic Valve 2 Issue

Indicates a fault within the tractor's remote hydraulic system, specifically pointing to a connection problem on the hydraulic valve or an issue with the spool position sensor value.

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

1. 1

   Inspect the wiring harness and electrical connectors at External Hydraulic Valve 2 for corrosion, damage, or loose pins (sensor/connection cause).

2. 2

   Check hydraulic and transmission filters for dirty oil or blockages that could cause poor spool performance.

3. 3

   Inspect mechanical linkages for wear in the links or bearings that actuate the spool valve, as play can prevent full movement and cause incorrect sensor readings.

4. 4

   Check for sticking valves by inspecting the spool valve detents for rust or debris that could restrict movement.

1. 1

   Relieve Hydraulic Pressure

   Before working on the hydraulic system, ensure the tractor is off and relieve any residual pressure in the remote valves.

2. 2

   Address Wiring/Sensor Faults

   If the diagnostic checks reveal a damaged connector or wiring harness at Valve 2, repair the wiring. If the spool position sensor itself has failed, it must be replaced (if available separately).

3. 3

   Clean and Free the Spool Valve

   If the valve is mechanically sticking due to rust or debris in the detents, clean the assembly. In some cases, the valve can be rebuilt using a seal kit to fix sticking or leaking issues.

4. 4

   Replace the Valve Assembly

   If the valve is internally damaged or if the manufacturer does not sell the sensor/detents separately (as is the case with some series where Massey Ferguson only sells the complete valve), you will need to unbolt the old valve from the hydraulic block and install a new complete spool valve assembly.

5. 5

   Bleed the System

   After replacing the valve or seals, bleed the hydraulic system to remove any trapped air.

6. 6

   Clear Codes

   Use a compatible diagnostic tool to clear the A.20.27 DTC from the onboard diagnostic system and test the remote hydraulics for proper operation.