Massey Ferguson A.21.12 – Hydraulic Control Module: External Hydraulic Valve 2 Issue

Malfunction in the second auxiliary hydraulic remote valve circuit, typically caused by an electrical connection problem to the valve, an out-of-range spool position sensor value, or a mechanical failure/blockage within the valve itself preventing it from operating correctly.

• 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
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Check the hydraulic fluid level and condition. Look for dark, burnt, or milky fluid (water contamination) and inspect the hydraulic filter for clogs.

2. 2

   Inspect the wiring harness and electrical connector going to External Hydraulic Valve 2 for corrosion, pushed-out pins, or chafed wires.

3. 3

   Use a compatible Massey Ferguson diagnostic tool to read the live data for Valve 2 and check if the spool position sensor is registering movement or is stuck/reading out of range.

4. 4

   Hook up a hydraulic pressure gauge to the rear remote couplers for Valve 2 to verify if the valve is receiving and holding the correct system pressure (typically 2200-3600 psi).

1. 1

   Depressurize the System

   Lower all implements to the ground, turn off the engine, and cycle the hydraulic controls to relieve all residual pressure in the system.

2. 2

   Drain/Catch Fluid

   Place a catch pan under the rear hydraulic valve block assembly.

3. 3

   Disconnect Electricals

   Unplug the electrical harness connector from External Hydraulic Valve 2.

4. 4

   Remove the Valve

   Unbolt the hydraulic lines/hoses connected to Valve 2. Remove the mounting bolts securing the valve slice to the main hydraulic control block.

5. 5

   Inspect/Replace

   If the issue was diagnosed as a failed spool position sensor or a burnt solenoid, replace the electronic actuator head if available separately. If the valve body is scored or internally bypassing, the entire valve section must be replaced.

6. 6

   Reassembly

   Install the new or repaired valve section using new O-rings between the valve slices. Torque the mounting bolts to OEM specifications.

7. 7

   Reconnect

   Reattach the hydraulic lines and plug in the electrical connector.

8. 8

   Fluid Top-Up

   Top up the hydraulic system with fresh OEM-spec UTTO (Universal Tractor Transmission Oil).

9. 9

   Clear Codes and Calibrate

   Use a diagnostic tool to clear the 0A.21.12 fault code. Run a hydraulic valve calibration routine (if required by the specific model's ECU) and test the remote couplers for proper operation.