Massey Ferguson 13.X.18 – TRANS1: Brake System Pressure Not Dropped When Brake Applied

The transmission controller is detecting an implausible condition in the braking circuit. When the operator applies the brake (or park brake), the system expects to see a corresponding drop or change in hydraulic/air pressure to actuate the mechanism. If the pressure sensor reports that the pressure remains high or unchanged, the system flags this code to prevent transmission drive against locked or dragging brakes.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6600 Series
• 6614
• 6615
• 6616
• 6700 S Series
• 6713 S
• 6714 S
• 6715 S
• 6716 S
• 6718 S
• 7600 Series
• 7615
• 7619
• 7620
• 7622
• 7624
• 7700 Series
• 7700 S Series
• 7715 S
• 7719 S
• 7720 S
• 7726 S
• 8600 Series
• 8660
• 8670
• 8680
• 8690
• 8700 Series
• 8700 S Series
• 8727 S
• 8730 S
• 8732 S
• 8737 S

1. 1

   Use a diagnostic tool to monitor live data from the brake pressure sensor while applying and releasing the brake. A frozen or out-of-range reading indicates a faulty sensor or wiring.

2. 2

   Inspect the wiring harness leading to the brake pressure sensor and brake solenoid valve for rub points, open circuits, shorts to ground, or corrosion inside the connectors.

3. 3

   Check the resistance of the brake solenoid valve coil with a multimeter and ensure it receives the correct voltage signal from the TRANS1 module when actuated.

4. 4

   If electrical circuits and sensors are functioning properly, check if the physical brake valve or pressure regulator valve is mechanically stuck.

1. 1

   Depressurize the System

   Safely park the tractor on level ground, turn off the engine, and actuate the brakes to relieve residual hydraulic or air pressure in the system.

2. 2

   Inspect and Clean Connectors

   Locate the brake pressure sensor and brake solenoid valve on the transmission brake valve block. Disconnect the electrical plugs and clean them with contact cleaner. Reconnect and test to see if the code clears.

3. 3

   Replace the Pressure Sensor

   If live data confirmed a dead sensor, unthread the old brake pressure sensor from the valve block. Install the new OEM sensor, taking care not to overtighten and damage the O-ring seal.

4. 4

   Replace the Solenoid Valve

   If the sensor is reading correctly but the pressure physically isn't dropping, the solenoid valve is likely stuck. Remove the retaining nut/clip, slide off the coil, and unthread the valve cartridge. Install the new solenoid valve.

5. 5

   Bleed the System

   If hydraulic lines were opened during the repair, bleed the brake system according to the OEM service manual to remove any trapped air.

6. 6

   Clear Codes and Test

   Connect your diagnostic tool, clear the 13.X.18 fault code from the TRANS1 module, and test drive the tractor to ensure the brakes apply and release smoothly without triggering the code.