Massey Ferguson 13.02.0B – TRANS1: Hydraulic Trailer Brake Solenoid Issue

The system has detected an electrical anomaly (such as an open circuit, short circuit, or abnormal current draw) in the solenoid circuit responsible for actuating the hydraulic trailer brakes. When the tractor's brake pedals are depressed, this solenoid regulates the hydraulic pressure sent to the trailer brake coupling.

• 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
• 8S.205
• 8S.225
• 8S.245
• 8S.265
• 8400 Series

1. 1

   Locate the hydraulic trailer brake valve assembly at the rear of the tractor and inspect the wiring harness and connector for corrosion, moisture ingress, or broken wires.

2. 2

   Disconnect the solenoid and use a multimeter to measure the resistance across the solenoid coil pins to check for an open circuit or dead short.

3. 3

   With the key ON, probe the harness side of the connector to ensure the TRANS1 module is delivering the correct voltage/PWM signal when the brake pedals are applied.

4. 4

   Connect a pressure gauge to the trailer brake coupling to check if the valve spool is mechanically jammed with debris (if the electrical circuit tests fine).

1. 1

   Preparation

   Park the tractor on a level surface, engage the park brake, turn off the engine, and remove the key.

2. 2

   Relieve Pressure

   Pump the brake pedals several times and operate the hydraulic remote levers to relieve any residual hydraulic pressure in the system.

3. 3

   Disconnect Electrics

   Disconnect the wiring harness connector from the faulty hydraulic trailer brake solenoid.

4. 4

   Remove the Solenoid

   Depending on the valve block design, either remove the retaining nut at the end of the solenoid stem to slide the electromagnetic coil off, or use a wrench to unthread the entire solenoid cartridge valve from the hydraulic block.

5. 5

   Inspect and Clean

   Check the hydraulic port for any metal shavings or debris that could have caused the valve to stick. Clean the mating surface.

6. 6

   Install the New Part

   Thread the new solenoid cartridge into the block (or slide the new coil over the existing stem) and tighten to the manufacturer's specified torque.

7. 7

   Reassembly

   Reconnect the electrical harness.

8. 8

   Testing

   Start the tractor and test the brake pedals. Verify hydraulic pressure at the rear trailer coupling.

9. 9

   Clear Codes

   Use the tractor's diagnostic interface (or a dealer diagnostic tool) to clear the 13.02.0B fault code from the TRANS1 module.