Massey Ferguson 13.03.18 – TRANS1: Brake System Pressure Not Dropped When Brake Applied Dyna VT (TRANS1)

Triggers when the system detects that the hydraulic or pneumatic brake pressure remains high despite the brake pedal being depressed. This typically indicates a faulty brake pressure sensor, a stuck brake pressure relief valve, or a malfunctioning brake pedal switch.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6614
• 6615
• 6616
• 6713 S
• 6714 S
• 6715 S
• 6716 S
• 6718 S
• 7465
• 7475
• 7480
• 7485
• 7490
• 7495
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 8450
• 8460
• 8470
• 8480
• 8650
• 8660
• 8670
• 8690

1. 1

   Verify Actual Pressure: Use a mechanical pressure gauge on the brake hydraulic test port to determine if the pressure is actually failing to drop, or if the sensor is just reporting a false value.

2. 2

   Sensor Voltage Check: Check the voltage of the braking pressure sensor (often designated as X135 or similar in the service manual). The voltage should be within the standard operating range (typically between 1V and 5V). If it is stuck at a high voltage regardless of pedal position, the sensor is likely faulty.

3. 3

   Pedal Switch Inspection: Inspect the brake pedal sensors/switches (often located in the pedal box). If the transmission does not recognize that the pedal has been pressed due to a faulty switch, it will flag a conflict between pedal position and system pressure.

4. 4

   Wiring Harness Check: Inspect the wiring harness connecting the brake pressure sensor to the TRANS1 module for shorts to power, which would artificially keep the pressure signal high.

1. 1

   Depressurize the System

   Park the tractor on a flat surface, engage the park lock, turn off the engine, and pump the brake pedals multiple times to relieve residual hydraulic/pneumatic pressure in the braking circuit.

2. 2

   Disconnect Power

   Disconnect the negative battery terminal to prevent electrical shorts and to reset the modules.

3. 3

   Replace the Faulty Component (Sensor)

   If the sensor is faulty: Locate the brake pressure sensor on the brake valve block (usually located near the rear axle/transmission housing). Unplug the electrical connector, unscrew the sensor, and install the new OEM sensor.

4. 4

   Replace the Faulty Component (Valve)

   If the valve is stuck: Locate the brake pressure relief valve. Remove the hydraulic lines (have a catch pan ready for fluid), unbolt the valve assembly, and replace it with a new unit.

5. 5

   Replace the Faulty Component (Pedal Switch)

   If the pedal switch is faulty: Access the pedal box in the cab and replace the bottom brake/clutch switch.

6. 6

   Bleed the Brakes

   If the hydraulic circuit was opened (e.g., replacing the valve), you must bleed the brake system according to the operator's manual to remove any trapped air.

7. 7

   Clear Codes and Calibrate

   Reconnect the battery. Connect a diagnostic tool (like AGCO EDT) to clear the 13.03.18 fault code from the TRANS1 module. Perform a test drive to ensure the brake pressure drops correctly on the live data feed when the pedal is applied.