CLAAS Id7627h / 7627h (408) – TR2 (A57-2): High-pressure brake accumulator faulty, torn

The internal diaphragm or bladder inside the high-pressure brake accumulator (Cumulator 5016) has ruptured or failed. The gas escapes into the hydraulic fluid, causing the accumulator to lose its energy reserve, forcing the hydraulic pump to inflate the braking circuit too frequently or failing to hold the required high-pressure braking threshold.

• CLAAS Axion 800 Series
• CLAAS Axion 810
• CLAAS Axion 850
• CLAAS Arion 500 Series
• CLAAS Arion 600 Series
• CLAAS Arion 510
• CLAAS Arion 640

1. 1

   Inspect the high-pressure brake accumulator (Cumulator 5016) directly for a torn diaphragm and complete loss of nitrogen pre-charge.

2. 2

   Inspect the surrounding hydraulic circuit, including valves, pipes, and switches, for external leaks causing rapid pressure drops.

3. 3

   Verify the readings of the Braking Pressure Sensor (B233) to ensure the fault is not caused by erratic pressure drop signals.

4. 4

   Inspect the high-pressure braking solenoid valve (Y329) for proper operation.

1. 1

   Depressurize the System

   Park the tractor on level ground, turn off the engine, and repeatedly depress the brake pedals to safely discharge any remaining hydraulic pressure in the high-pressure braking circuit.

2. 2

   Locate the Accumulator

   Locate 'Cumulator 5016' (the high-pressure brake accumulator) on the transmission/hydraulic valve block.

3. 3

   Remove and Replace

   Unthread the faulty accumulator from the hydraulic block and install the new OEM replacement accumulator. Ensure the mating surfaces are clean and the correct torque specifications are applied.

4. 4

   Re-pressurize

   Start the tractor. The hydraulic pump will run to reinflate the high-pressure braking circuit.

5. 5

   Clear Codes

   Connect the CLAAS diagnostic tool (METADIAG / tool n° 60 05 033 249) to the TR2 (A57-2) module and clear the Id7627h error code.

6. 6

   Test Drive

   Operate the tractor and apply the brakes multiple times to ensure the anomaly does not reappear and the pump does not cycle excessively.