Massey Ferguson 14.00.03 – TRANS1: High Brake System Pressure

The pressure sensor monitoring the high-pressure braking circuit is reporting a value that exceeds the maximum allowable threshold. This can be caused by a genuine over-pressure situation in the hydraulic or air brake circuit, such as a stuck relief valve, or more commonly, a faulty pressure sensor or a short-circuit in the sensor wiring sending a false high-voltage signal to the controller.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6465
• 6475
• 6480
• 7465
• 7475
• 7480
• 7614
• 7615
• 7616
• 7618
• 8650
• 8660
• 8670

1. 1

   Verify Actual Pressure: Connect a mechanical pressure gauge to the high-pressure brake test port to see if the system is genuinely over-pressurizing. If the mechanical gauge reads normal but the dashboard/ECU reads high, the sensor or wiring is at fault.

2. 2

   Inspect Sensor Wiring (Connector X495): Check the wiring harness and the connector at the brake pressure sensor for corrosion, moisture, or a short-to-power (which would cause a false high reading).

3. 3

   Check Sensor Power Supply: Verify that the voltage converter supplying the high-pressure brake sensor is outputting the correct reference voltage (usually 5V). A power supply problem can trigger erratic pressure codes.

4. 4

   Inspect the High-Pressure Brake Valve: If the mechanical pressure is actually too high, inspect the high-pressure brake valve and the pressure relief valve for sticking or blockages.

1. 1

   Depressurize the System

   Park the tractor on a level surface, turn off the engine, and pump the brake pedals repeatedly to safely relieve all residual hydraulic/air pressure in the accumulator and brake lines.

2. 2

   Locate the Sensor

   Locate the high-pressure brake sensor on the brake valve block/air supply unit (location varies slightly by series, usually near the right-hand LS cover plate or main hydraulic block).

3. 3

   Disconnect Wiring

   Carefully unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Using a wrench, unscrew the faulty pressure sensor. Have a rag ready to catch any minor fluid drips.

5. 5

   Install the New Sensor

   Thread the new OEM pressure sensor into the port. Tighten to the torque specification outlined in your specific model's service manual.

6. 6

   Reconnect and Test

   Reconnect the wiring harness. Start the tractor, allow the brake system to charge, and check for leaks.

7. 7

   Clear Codes

   Use the tractor's SIS (System Information Screen) or a dealer diagnostic tool to clear the 14.00.03 fault code from the TRANS1 module.