Massey Ferguson 04.03.50 – TRANS: Transmission Filter Blocked (TRANS)

Triggered when the transmission filter blockage sensor (often designated as sensor X20 in Massey Ferguson wiring diagrams) detects a pressure differential indicating that the transmission/hydraulic oil filter is clogged and restricting fluid flow.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 4707
• 4708
• 4709
• 4710
• 5600 Series
• 5700 Series
• 6700 Series
• 7714S
• 7719S

1. 1

   Check fluid temperature: Cold, thick hydraulic oil can cause a false pressure differential. Verify if the code persists after the tractor reaches normal operating temperature.

2. 2

   Inspect the sensor and wiring: Locate the transmission filter blockage sensor (Sensor X20) on the filter housing. Check the wiring harness and connector for damage, corrosion, or a short circuit.

3. 3

   Check for brake wear (Crucial Step): Disintegration of internal brake discs is a highly common cause. Fibre linings break up and travel through the shared oil system, heavily clogging the transmission filter.

1. 1

   Prepare the Machine

   Park the tractor on a level surface, engage the parking brake, and turn off the engine.

2. 2

   Drain the Fluid

   Place a large catch pan under the transmission drain plug. Drain the transmission/hydraulic fluid. (Note: If the fluid is relatively new and uncontaminated, it can be drained into a clean container for reuse, but replacement is recommended if the filter is heavily blocked).

3. 3

   Remove the Filter

   Locate the transmission hydraulic filter housing. Unscrew the housing/canister and remove the blocked filter element.

4. 4

   Inspect for Debris

   Carefully inspect the pleats of the old filter. If you find heavy metal filings or fibrous brake disc material, do not just replace the filter. The tractor will require a teardown of the rear end to replace the brake discs and a complete system flush to prevent catastrophic transmission damage.

5. 5

   Clean the Suction Screen

   Locate and remove the hydraulic suction filter screen. Clean it thoroughly with solvent and compressed air, or replace it if damaged.

6. 6

   Install New Parts

   Lubricate the O-rings on the new transmission filter with clean hydraulic oil. Install the new filter element and tighten the housing to the manufacturer's specified torque.

7. 7

   Refill Fluid

   Refill the transmission with the correct OEM-specified hydraulic/transmission fluid (e.g., Permatran 821XL) to the proper level on the dipstick or sight glass.

8. 8

   Test

   Start the tractor and let it idle. Check the filter housing for leaks. The fault code should move to an inactive state or clear from the dash once normal fluid pressure is restored.