Massey Ferguson 0A.72.28 – Basic Control ECU: External Hydraulic Valve 7 Issue

A malfunction associated with the 7th electro-hydraulic rear remote valve (spool valve). This indicates an electrical circuit issue (such as an open circuit, short to ground, or short to power), a communication failure on the CAN bus, or a mechanical condition where the valve spool is stuck and cannot reach its commanded position.

• 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 electrical connector at External Hydraulic Valve 7 at the rear valve stack for dirt, moisture, corrosion, or pushed-back pins.

2. 2

   Trace the wiring harness from Valve 7 back to the Basic Control ECU, looking for rub points, chafing, or pinched wires that could cause a short to ground.

3. 3

   Perform a swap test by exchanging the electrical connector from Valve 7 with an adjacent, known-good valve (e.g., Valve 6). If the fault code changes to the adjacent valve, the valve itself is faulty. If the code remains 0A.72.28, the issue is in the wiring harness or the ECU.

4. 4

   Use a multimeter to measure the resistance of the solenoid coil on Valve 7 to ensure it is within the manufacturer's specified range.

1. 1

   Depressurize the System

   Turn off the tractor and cycle the hydraulic controls to relieve any residual pressure in the system.

2. 2

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts and ensure safety.

3. 3

   Clean the Area

   Thoroughly clean the rear hydraulic valve stack with brake cleaner or a pressure washer to prevent dirt from entering the hydraulic system during disassembly.

4. 4

   Disconnect Wiring

   Unplug the electrical connector from the faulty Valve 7 slice.

5. 5

   Remove the Valve Slice

   Remove the hydraulic lines connected to the specific valve. Unbolt the tie rods (long bolts) that hold the modular valve stack together. Carefully slide out the faulty Valve 7 slice. Note: Be extremely careful not to lose or damage the O-rings that seal the passages between the valve slices.

6. 6

   Install the New Valve

   Install the new electric spool slice, ensuring that new O-rings are placed between the slices. Reinsert the tie rods and torque them to the OEM specification in an alternating pattern to ensure an even seal.

7. 7

   Reassembly

   Reconnect the hydraulic lines and the electrical connector.

8. 8

   Calibration

   Reconnect the battery. Start the tractor and check for leaks. Note that new electric spool slices often need to be calibrated/programmed to the tractor's ECU using a dealer diagnostic tool (like the AGCO Electronic Diagnostic Tool).