Fendt 08.1.FD – A050 ECU (Basic Control Unit): Y077 [HKH] - EHR (EPC) cut-off valve, rear power lift

Pilot control actuator jams. The valve becomes locked, and the pilot pressure is turned OFF. This is frequently caused by mechanical jamming of the pilot control or main actuator due to contamination in the hydraulic oil.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• FENDT 300 Vario (COM III)
• FENDT 400 Vario (COM III)
• FENDT 700 Vario (COM III)
• FENDT 800 Vario (COM III)
• FENDT 900 Vario (COM III)
• 919
• 922
• 924
• 927
• 930
• 933
• 936

1. 1

   Inspect hydraulic fluid for dirt, debris, or metal shavings, as contamination is the primary cause of actuator jamming.

2. 2

   Check electrical connections to the Y077 valve on the rear valve block and verify it receives approximately 12-14 VDC when active.

3. 3

   Verify the passive bus system to ensure bus ends are properly sealed off with terminating resistors, as communication errors can mimic mechanical lockouts.

4. 4

   Check for brief pilot control pressure dips, which can cause the valve actuator to fall short and lock.

1. 1

   Release hydraulic pressure

   Ensure the tractor engine is off (idle position) and release all hydraulic pressure. If equipped with hydraulic trailer brakes, release the pressure with the trailer brake button.

2. 2

   Locate valve

   Locate the Y077 valve, which is situated on the rear valve block at the rear of the tractor.

3. 3

   Disconnect electrical connector

   Unplug the Power Beyond electrical connector from the entry plate.

4. 4

   Loosen tie bolt nuts

   Loosen the tie bolt nuts on the valve block in the correct numbered sequence.

5. 5

   Remove tie bolt nuts

   Remove the nuts on the three long tie bolts from the entry plate.

6. 6

   Remove entry plate

   Carefully remove the entry plate sideways to access the valve stack.

7. 7

   Remove faulty valve

   Remove the faulty Y077 rear EHR cut-off valve.

8. 8

   Install replacement valve

   Install the replacement Y077 valve.

9. 9

   Reassemble components

   Reassemble the entry plate, tighten the tie bolts to the specified torque, and reconnect the electrical connector.

10. 10

    Replace filters and flush fluid

    Replace the hydraulic oil filters and flush the hydraulic fluid if contamination was found, otherwise the new valve will jam again.