Massey Ferguson 04.01.50 – TRANS: Transmission Filter Blocked

The transmission filter blockage switch/sensor (often designated as sensor X20) has detected a pressure drop or restriction in the hydraulic/transmission circuit. This indicates that the transmission oil filter is clogged, which restricts oil flow, forces the pump to work harder, and can lead to pump cavitation or the activation of the bypass valve.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 4707
• 4708
• 4709
• 4710
• 5710SL
• 5711SL
• 5712SL
• 5713SL

1. 1

   Check Oil Temperature: Cold, thick hydraulic oil can sometimes trigger a false blockage alarm. Verify if the code persists once the tractor reaches normal operating temperature.

2. 2

   Inspect the Sensor and Wiring: The blockage sensor itself can fail or suffer wiring damage, triggering a false 04.01.50 code. Check the sensor (usually located on the right-hand side of the gearbox near the filter housing) for electrical continuity and secure connections.

3. 3

   Check for Brake Wear (Crucial): Massey Ferguson tractors utilize a single-oil system. A very common cause of a blocked transmission filter is the deterioration of the internal brake discs. If the fiber linings wear down to the metal, the debris goes directly into the transmission oil and clogs the filter.

4. 4

   Inspect the Oil: Drain a small amount of transmission fluid and check for metal filings, brake lining material, or heavy sludge.

1. 1

   Stop Operation

   Halt the tractor immediately. Continuing to drive with a blocked filter starves the hydraulic pump and can cause catastrophic transmission or pump damage.

2. 2

   Drain the Transmission Fluid

   Place a clean drain pan under the transmission and drain the oil. Inspect the drained oil carefully for cross-contamination or brake debris. (Note: If heavy metal or brake material is found, the rear axle/brakes must be stripped and repaired, and the entire back-end flushed before proceeding).

3. 3

   Remove the Filter Housing

   Locate the transmission filter housing, typically found on the right-hand side of the transmission behind a protective plate held by bolts.

4. 4

   Replace the Filter

   Remove the clogged filter element. Clean the inside of the filter housing and inspect the suction strainer (if equipped) for debris. Install the new OEM transmission filter.

5. 5

   Replace the Sensor (If Faulty)

   If diagnostics proved the filter was clean but the sensor was faulty, unthread the old blockage switch/sensor and install the replacement.

6. 6

   Refill the System

   Refill the transmission with the exact AGCO-specified transmission/hydraulic oil for your model to the correct level on the sight glass/dipstick.

7. 7

   Test and Clear Codes

   Start the tractor and let it idle. Check for leaks around the filter housing. The warning light and 04.01.50 code should clear.