Massey Ferguson T167 – TRANS1: High Pressure Brake System Pressure Not Dropping DYNA 6

The system detects that the hydraulic pressure within the high-pressure braking system is failing to drop or bleed off as expected after the brakes are released. This typically points to a sensor reading error (stuck high voltage) or a mechanical issue preventing the brake fluid pressure from returning to the reservoir.

• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• Interim Tier 4 (2012-2015)
• 5709
• 5710
• 5711
• 5712
• 5713
• 6465
• 6475
• 6480
• 6614
• 6615
• 6616
• 6713 S
• 6714 S
• 6715 S
• 6716 S
• 6718 S
• 7715 S
• 7716 S
• 7718 S
• 7720 S
• 7722 S
• 7724 S
• 7726 S

1. 1

   Check the brake pressure sensor (sensor cause): If the brakes release normally but the code persists, the issue is likely the sensor. Look for a stuck signal or an accompanying 14.01.0A code.

2. 2

   Inspect the wiring harness (wiring cause): Check the connection between the brake pressure sensor and the TRANS1 module for a short to voltage that would cause the ECU to read artificially high pressure.

3. 3

   Verify if the brakes are physically dragging (mechanical cause): If the brakes are dragging, the issue is hydraulic/mechanical, such as a stuck brake valve or blocked return line.

4. 4

   Check for air or contamination in the brake lines (hydraulic cause): The high-pressure braking system and assisted brake master cylinders may require bleeding.

1. 1

   Depressurize the System

   Ensure the tractor is turned off, the parking brake is engaged, and hydraulic pressure is relieved before opening any brake lines.

2. 2

   Locate the Sensor

   Locate the high-pressure brake sensor. Depending on the exact model and options, this will be the Trailer Brake Pressure Sensor or the Handbrake Pressure Sensor located on the brake valve block.

3. 3

   Test/Replace the Sensor

   Disconnect the sensor. If diagnostics point to a faulty sensor (reading high pressure when the system is depressurized), unthread the old sensor and install the replacement.

4. 4

   Bleed the Brakes

   Locate the bleed screws on the assisted brake master cylinders and the high-pressure brake lines. Attach a bleed hose to the bleed screw locations. Follow the OEM procedure to pump the brakes and bleed the system until fluid runs clear of air bubbles.

5. 5

   Clear Codes

   Reconnect the sensor harness, turn the ignition on, and use a diagnostic tool to clear the T167 / 14.01.0B fault code from the TRANS1 module. Test drive to ensure the pressure drops normally upon brake release.