Fendt A.1.38 – Spool Valves 1–4: Spool valve fault, valve 3.

The main piston cannot return to the neutral position because of oil contamination. This is flagged as a DANGER! condition because undefined and uncontrolled hydraulic functions can occur. The valve remains set and fails to neutralize.

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 820 Vario greentec COM III
• Fendt 900 Vario COM III

1. 1

   Check the manual actuation of the valve. It must not have any play.

2. 2

   Check the slider return to ensure that the slider goes into the middle (neutral) position by itself. If it binds, the piston is physically stuck.

3. 3

   Inspect the hydraulic fluid and filters for debris, metal shavings, or degraded oil, as oil contamination is the root cause.

1. 1

   Relieve hydraulic pressure

   Turn off the tractor and relieve all hydraulic pressure from the system before servicing the spool valves.

2. 2

   Address contamination

   Drain the contaminated hydraulic oil, flush the system, and replace the hydraulic filters to prevent the issue from recurring or damaging other valves.

3. 3

   Inspect Valve 3 (Y017)

   Locate auxiliary control valve 3. Test the manual slider to see if it springs back to the neutral position.

4. 4

   Clean or replace valve

   If the main piston is jammed due to debris, the valve must be removed. Depending on the severity of the internal scoring from the contamination, the spool valve assembly will either need to be thoroughly cleaned or completely replaced.

5. 5

   Re-test system

   After reassembly and refilling with clean hydraulic fluid, actuate the valve to ensure it returns to neutral and clear the A.1.38 fault code from the terminal.