Massey Ferguson 13.01.0B – TRANS1: Hydraulic Trailer Brake Solenoid Issue

This indicates an electrical or operational malfunction (such as an open circuit, short circuit, or abnormal current draw) in the solenoid valve responsible for controlling the hydraulic pressure sent to the trailer brakes.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Inspect the wiring harness and connector leading to the hydraulic trailer brake solenoid (located on the transmission/rear axle valve block) for chafing, corrosion, or loose pins.

2. 2

   Disconnect the solenoid and measure the resistance across the coil pins using a multimeter. Compare the reading to OEM specifications to determine if the coil is internally shorted or open.

3. 3

   Back-probe the connector and actuate the brakes to verify that the TRANS1 module is sending the correct voltage/signal to the solenoid.

4. 4

   If the electrical circuit is intact, check for mechanical binding in the valve cartridge or a hydraulic pressure drop in the trailer brake circuit.

1. 1

   Park the tractor on a level surface, engage the parking brake, lower all implements, and turn off the engine.

   Relieve any residual hydraulic pressure by pumping the brake pedals.

2. 2

   Locate the hydraulic trailer brake valve assembly on the rear transmission housing.

3. 3

   Thoroughly clean the area around the valve block to prevent dirt from entering the hydraulic system.

4. 4

   Disconnect the electrical harness from the faulty trailer brake solenoid.

5. 5

   Remove the retaining nut at the end of the solenoid stem to slide the coil off, OR use a wrench to unthread the entire solenoid valve cartridge from the valve block.

   This depends on whether the coil or the whole cartridge has failed.

6. 6

   Lubricate the O-rings on the new valve cartridge/solenoid with clean hydraulic oil.

7. 7

   Thread the new solenoid into the valve block and tighten to the OEM torque specification.

8. 8

   Reconnect the electrical harness.

9. 9

   Start the tractor, test the trailer brake actuation, check for hydraulic leaks, and use a diagnostic tool to clear the 13.01.0B fault code from the TRANS1 module.