Fendt A.1.3A – ELECTRICAL VALVES VALVE 3 / VENDI: Spool valve fault, valve 3 (Y017) - Main piston deflected too far.

The main piston inside the 3rd auxiliary control valve (Y017) has traveled beyond its normal operating range or is physically unable to return to its neutral, centered position. The system forces the valve into the neutral position to prevent uncontrolled hydraulic movements. The most common cause is hydraulic oil contamination causing the spool to stick.

• 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 Farmer 400 Vario
• Fendt Favorit 700 Vario
• Fendt 800 Vario (including 820 Vario Greentec)
• Fendt Favorit 900 Vario

1. 1

   Check the hydraulic oil for dirt, metal shavings, or other contamination.

2. 2

   Check the control pressure at test port M5. Verify the diaphragm accumulator and RV7/FP are functioning correctly.

3. 3

   Inspect the wiring harness and connector X328 (specifically pins 23, 24, and 26) which supplies the Y017 valve for damage, corrosion, or poor connection.

4. 4

   Check the valve actuator manually. The actuator must not have any play and must be able to spring back to the center position by itself.

1. 1

   Depressurize the System

   Ensure the tractor is turned off and relieve all hydraulic pressure from the system before beginning work.

2. 2

   Locate Valve Y017

   Locate the 3rd auxiliary control valve (Y017). On models like the Favorit 900, this is located on the underside of the central control block. Accessing it may require unscrewing the right step and pulling the right auxiliary tank outwards.

3. 3

   Remove and Inspect

   Remove the Y017 valve block. Inspect the spool and the spool bore for scoring, excessive wear, or trapped debris.

4. 4

   Clean and Recalibrate

   If the valve is simply dirty, thoroughly clean the valve block and pilot circuits. Reinstall the valve and use the FENDIAS diagnostic tool to recalibrate the spool valves.

5. 5

   Replace if Worn

   If the spool is physically worn, scored, or if the fault persists after cleaning and recalibration, the entire auxiliary control valve must be replaced.

6. 6

   Fluid Service

   If contamination was found, drain the hydraulic fluid, replace the hydraulic filters, and refill with clean, OEM-approved hydraulic fluid to prevent the new valve from failing.