Massey Ferguson 13.02.18 – TRANS1: Brake System Pressure Not Dropped When Brake Applied Dyna VT (TRANS1)

This code indicates that when the operator applies the brakes, the transmission control system expects to see a corresponding drop or change in the brake system hydraulic pressure, but the pressure remains high. This typically points to a hydraulic pressure relief failure, a mechanically stuck brake valve, or a faulty pressure sensor sending an incorrect "high pressure" signal to the controller.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6614
• 6615
• 6616
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 8660
• 8670
• 8680
• 8690
• 8727
• 8730
• 8732
• 8735
• 8737

1. 1

   Connect a diagnostic terminal and monitor live data for the brake pressure sensor to see if readings are stuck at a high value regardless of pedal position.

2. 2

   Perform a manual pressure test by connecting a hydraulic pressure gauge to the brake valve test port to verify if physical pressure actually drops when brakes are applied.

3. 3

   Inspect the wiring harness and connectors going to the brake pressure sensor and brake solenoid valve for shorts to voltage, damaged pins, or corrosion.

4. 4

   Check the brake solenoid valve and main hydraulic brake valve for sticking spools or debris blocking the return/venting ports.

1. 1

   Prepare tractor for service

   Park the tractor on level ground, engage the park lock, turn off the engine, and pump the brake pedals several times to relieve any residual hydraulic pressure in the accumulators and brake lines.

2. 2

   Replace brake pressure sensor

   If the manual gauge test shows physical pressure drops but the sensor reads high (electrical fault), locate the brake pressure sensor on the brake valve block. Disconnect the plug, clean contacts, and if necessary, install a replacement OEM sensor torqued to manufacturer specifications.

3. 3

   Service brake solenoid valve

   If the manual gauge test proves the physical pressure is not dropping (hydraulic fault), locate the brake solenoid valve. Remove the solenoid coil and carefully extract the valve cartridge. Inspect the O-rings and valve spool. If the spool is scored or stuck, replace the brake solenoid valve or the entire cardan brake valve block.

4. 4

   Reassemble and bleed system

   Reconnect all hydraulic lines and electrical connectors. Bleed the tractor's brake system according to the service manual to remove any trapped air.

5. 5

   Clear codes and test

   Turn the ignition on, connect the diagnostic tool, clear the 13.02.18 fault code from the TRANS1 module, and perform a test drive to ensure the brakes apply and release correctly without triggering the code.