Massey Ferguson A.20.29 – Dash / Hydraulic Valve Module / Mid Mount Valve Module: External Hydraulic Valve 2 Issue

Indicates a malfunction, communication error, or out-of-range signal associated with the tractor's second external hydraulic remote valve (spool valve). This fault typically manifests as remote hydraulics that are slow, weak, or completely dead when attempting to operate implements.

• 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

   Inspect the hydraulic/transmission oil for contamination (dirt or metal shavings) and check if the hydraulic filter is blocked, which can restrict flow to the valves.

2. 2

   Check the wiring harness and solenoid connector at External Hydraulic Valve 2. Look for wire rub points, open circuits, shorts to ground, or loose pins.

3. 3

   Test the spool position sensor value and measure the solenoid coil resistance with a multimeter to ensure they are within spec.

4. 4

   Ensure the external hydraulic couplers are not damaged or blocked, which can simulate a dead valve.

1. 1

   Preparation

   Park the tractor on a level surface, lower all attached implements to the ground, turn off the engine, and relieve all hydraulic system pressure.

2. 2

   Address Basic Faults

   If the diagnostic checks revealed dirty oil or a clogged filter, drain the hydraulic fluid, replace the transmission/hydraulic filter, and refill with clean OEM-spec fluid.

3. 3

   Wiring Repair

   If the harness at Valve 2 is damaged, repair the broken wires or replace the solenoid connector pigtail.

4. 4

   Valve Removal

   If the electrical inputs are correct but the valve remains unresponsive or throws the position sensor code, the spool valve is likely mechanically stuck or has failed internal seals. Unbolt the External Hydraulic Valve 2 assembly from the valve stack.

5. 5

   Rebuild or Replace

   Disassemble the spool valve on a clean workbench. Inspect the spool and bore for scoring. If the valve is salvageable, rebuild it using an OEM spool valve repair kit (replacing all O-rings and seals). If the bore is heavily scored or the sensor has failed internally, replace the entire spool valve assembly.

6. 6

   Reinstallation

   Mount the rebuilt or new valve back onto the stack, torque the bolts to spec, and reconnect the electrical harness.

7. 7

   Code Clearing

   Connect a compatible diagnostic tool or interface device to the tractor to clear the 0A.20.29 fault code. Test the remote hydraulics with an implement to confirm full pressure and flow.